CALCULATION OF REGISTRATION FEE

Title of Each Class of Securities to be Registered	Amount to be Registered(2)	Proposed Maximum Offering Price Per Unit	Proposed Maximum Aggregate Offering Price	Amount of Registration Fee(3)
Ordinary Shares, par value 50 pence each(1)	25,555,556	$18.00	$460,000,008.00	$55,752.01

(1) American Depositary Shares (“ADSs”), evidenced by American Depositary Receipts, issuable upon deposit of Ordinary Shares, par value 50 pence each (“Ordinary Shares”), of Amarin Corporation plc are registered on a separate registration statement. Each ADS represents one Ordinary Share.

(2) Includes 3,333,333 ADSs which may be purchased by the underwriters upon exercise of the underwriters’ option to purchase additional ADSs.

(3) Calculated in accordance with Rule 456(b) and 457(r) of the Securities Act of 1933, as amended.

Filed Pursuant to Rule 424(b)(5)
File No. 333-216385

Prospectus supplement

(To Prospectus dated March 1, 2017)

22,222,223 American Depositary Shares

Amarin Corporation plc

Representing 22,222,223 Ordinary Shares

We are offering 22,222,223 American Depositary Shares, or ADSs. Each ADS represents one of our ordinary shares, par value £0.50 per share. Our ADSs are listed on The Nasdaq Global Market under the symbol “AMRN”. On July 18, 2019, the last reported sale price of our ADSs on The Nasdaq Global Market was $18.90 per share.

Investing in our ADSs involves a high degree of risk. Please read “Risk Factors” beginning on page S-9 of this prospectus supplement and in the documents incorporated by reference into this prospectus supplement.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

	Per ADS		Total
Public offering price	$	18.000	$	400,000,014
Underwriting discounts and commissions		0.765		17,000,001
Proceeds to Amarin Corporation plc, before expenses		17.235		383,000,013

Delivery of the ADSs is expected to be made on or about July 23, 2019. We have granted the underwriters an option for a period of 30 days to purchase up to an additional 3,333,333 ADSs. If the underwriters exercise the option in full, the total underwriting discounts and commissions payable by us will be approximately $19,550,000 and the total proceeds to us, before expenses, will be approximately $440,450,008.

Joint Book-Running Managers

J.P. Morgan Goldman Sachs & Co. LLC Jefferies Cantor

Co-Managers

H.C. Wainwright & Co. Roth Capital Partners

The date of this prospectus supplement is July 18, 2019.

Table of contents

Prospectus supplement

About this prospectus supplement	S-1
Prospectus supplement summary	S-2
The offering	S-5
Cautionary statement regarding forward-looking statements	S-7
Risk factors	S-9
Description of American Depositary Shares	S-12
Use of proceeds	S-22
Dilution	S-23
Certain U.K. tax considerations	S-24
Certain U.S. federal income tax considerations for U.S. holders	S-25
Underwriting	S-31
Legal matters	S-40
Experts	S-40
Where you can find more information	S-40
Incorporation of certain information by reference	S-41

Prospectus

Prospectus summary	1
Risk factors	4
Special note regarding forward-looking statements	4
Description of securities	6
Certain material U.K. tax considerations	34
Certain material Irish tax considerations	36
Use of proceeds	38
Ratio of earnings to fixed charges	39
Selling security holders	39
Plan of distribution	40
Legal matters	43
Experts	43
Incorporation of certain information by reference	44
Where you can find more information	45

S-i

You should rely only on the information contained in or incorporated by reference in this prospectus supplement and the accompanying prospectus. We have not, and the underwriters have not, authorized anyone to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted. You should assume that the information appearing in this prospectus supplement, the accompanying prospectus and the documents incorporated by reference in this prospectus supplement and the accompanying prospectus is accurate only as of the date of those respective documents. Our business, financial condition, results of operations and prospects may have changed since those dates. You should read this prospectus supplement, the accompanying prospectus and the documents incorporated by reference in this prospectus supplement and the accompanying prospectus in their entirety before making an investment decision. You should also read and consider the information in the documents to which we have referred you in the sections of this prospectus supplement and accompanying prospectus entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.”

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About this prospectus supplement

This prospectus supplement and the accompanying prospectus form part of a registration statement on Form S-3 (File No. 333-216385) that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration process on March 1, 2017, which registration statement was automatically effective upon filing. This document contains two parts. The first part consists of this prospectus supplement, which provides you with specific information about this offering. The second part, the accompanying prospectus, provides more general information, some of which may not apply to this offering. Generally, when we refer only to the “prospectus,” we are referring to both parts combined.

In this prospectus supplement, the “Company,” “Amarin,” “we,” “us,” “our” and similar terms refer to Amarin Corporation plc and its subsidiaries on a consolidated basis. References to our “ordinary shares” or “common shares” refer to the ordinary shares of Amarin Corporation plc. References to “ADSs” refer to American Depositary Shares, each of which represents one ordinary share of Amarin Corporation plc.

All references in this prospectus supplement to our consolidated financial statements include, unless the context indicates otherwise, the related notes.

We have not, and the underwriters have not, authorized anyone to provide you with any information other than information contained or incorporated by reference in this prospectus supplement and the accompanying prospectus or any free writing prospectus prepared by or on behalf of us or to which we have referred you. If the description of the offering varies between this prospectus supplement and the accompanying prospectus, you should rely on the information in this prospectus supplement. We and the underwriters take no responsibility for and can provide no assurance as to the reliability of, any other information that others may give you.

If the description of the offering varies between any free writing prospectus we have authorized for use in connection with this offering and this prospectus supplement, you should rely on the information in such free writing prospectus.

You should assume that the information in this prospectus supplement, the accompanying prospectus, the documents incorporated by reference herein and therein and in any free writing prospectus we have authorized for use in connection with this offering is accurate only as of the respective dates of those documents in which such information is contained, regardless of the time of delivery of this prospectus supplement or any sale of shares of common stock. Our business, financial condition, results of operations and prospects may have changed since those dates.

Any statement made in this prospectus supplement or in a document incorporated by reference in this prospectus supplement will be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement or in any other subsequently filed document that is also incorporated or deemed to be incorporated by reference in this prospectus supplement modifies or supersedes that statement. Any statement so modified or superseded will not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement. See “Incorporation of Certain Information by Reference” in this prospectus supplement.

We are not, and the underwriters are not, making an offer to sell these securities in any jurisdiction where the offer or sale is not permitted.

This prospectus supplement, the accompanying prospectus, and the information incorporated by reference herein and therein includes trademarks, service marks and trade names owned by us or other companies. All trademarks, service marks and trade names included or incorporated by reference into this prospectus supplement or the accompanying prospectus are the property of their respective owners.

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Prospectus supplement summary

The following summary of our business highlights some of the information contained elsewhere in or incorporated by reference into this prospectus supplement or the accompanying prospectus. Because this is only a summary, however, it does not contain all of the information that may be important to you. You should carefully read this prospectus supplement and the accompanying prospectus, including the documents incorporated by reference herein and therein, which are described under “Where You Can Find More Information” and “Incorporation of Certain Information by Reference” in this prospectus supplement and the accompanying prospectus. You should also carefully consider the matters discussed in the section in this prospectus supplement entitled “Risk Factors” and in the accompanying prospectus and in other periodic reports incorporated by reference herein and therein.

Our company

We are a pharmaceutical company with expertise in omega-3 fatty acids and lipid science focused on the commercialization and development of therapeutics to improve cardiovascular, or CV, health and reduce CV risk.

Our lead product, Vascepa^® (icosapent ethyl) capsules, is approved by the U.S. Food and Drug Administration, or FDA, for use as an adjunct to diet to reduce triglyceride, or TG, levels in adult patients with severe (TG ³500 mg/dL) hypertriglyceridemia. In January 2013, we began selling and marketing Vascepa in the United States by prescription only based on the FDA-approved MARINE indication for use in patients with severe (TG ³500 mg/dL) TG levels. We sell 1-gram and 0.5-gram capsule sizes of Vascepa principally to a limited number of major wholesalers, as well as selected regional wholesalers and specialty pharmacy providers, or collectively, our distributors or our customers, that in turn resell Vascepa to retail pharmacies for subsequent resale to patients and healthcare providers.

Since our inception, we have devoted substantial resources to our research and development efforts, most significantly our Vascepa cardiovascular outcomes trial, REDUCE-IT^™. We announced topline results from the REDUCE-IT study on September 24, 2018. On November 10, 2018, we publicly presented primary results of the REDUCE-IT study at the 2018 Scientific Sessions of the American Heart Association, or AHA, and the results were concurrently published in The New England Journal of Medicine. REDUCE-IT met its primary endpoint demonstrating a 25% relative risk reduction, or RRR, to a high degree of statistical significance (p<0.001), in first occurrence of major adverse cardiovascular events, or MACE, in the intent-to-treat patient population with use of Vascepa 4 grams/day as compared to placebo. REDUCE-IT also showed a 26% RRR in its key secondary composite endpoint of cardiovascular death, heart attacks and stroke (p<0.001). On March 18, 2019, we publicly presented the total cardiovascular events results, and the method of calculating such events, of the REDUCE-IT study at the American College of Cardiology’s (ACC) 68^th Annual Scientific Session in March 2019, and the total events results and methods were concurrently published in the Journal of the American College of Cardiology. Included in such results were that Vascepa reduced total events, first and subsequent events, by 30% compared to placebo, reflecting that for every 1,000 patients treated for five years with Vascepa versus placebo approximately 159 MACE could be prevented with Vascepa.

On March 28, 2019, we submitted a supplemental new drug application (sNDA) to the FDA seeking an expanded indication for Vascepa in the United States based on the results of the REDUCE-IT study. The indication we are seeking pertains to use of Vascepa to reduce cardiovascular events in at-risk patients. Based on the final results of REDUCE-IT, we plan to continue to develop Vascepa commercially in major markets around the world. On March 28, 2019, the American Diabetes Association, or ADA, issued important updates to the Standard of Medical Care in Diabetes for 2019, including a recommendation for the use of icosapent ethyl in treating at-risk patients based on the results of the REDUCE-IT cardiovascular outcomes study.

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We promote Vascepa directly in the United States. Such promotion, prior to results of the REDUCE-IT study, was based on demonstrated changes in biomarkers based on the MARINE study and, as to healthcare professionals with respect to cardiovascular risk reduction potential, the ANCHOR study of Vascepa in patients with persistent high (200-499 mg/dL) TGs after statin therapy. Because prior to results of the REDUCE-IT study we did not have outcomes data regarding the clinical effect of Vascepa and because a substantial portion of our resources were being spent on the REDUCE-IT study, prior to REDUCE-IT results our commercialization of Vascepa was somewhat limited. Subsequent to learning the positive cardiovascular outcomes results of the REDUCE-IT study, we have begun increasing our promotion of Vascepa.

Recent developments

On May 29, 2019, we announced that our sNDA for Vascepa was accepted for filing and granted Priority Review designation by the FDA. The Prescription Drug User Fee Act (PDUFA) goal date assigned by the FDA for this sNDA is September 28, 2019. Because of the Priority Review designation, the timing of this PDUFA date is four months earlier than the anticipated standard ten-month review for applications.

As of the date of this Preliminary Prospectus Supplement, the FDA has not informed us whether it plans to hold an advisory committee (AdCom) meeting to discuss this application, nor has the FDA informed us of the subject matter intended to be the focus of a potential AdCom meeting if one were to be scheduled. While such notification now would be considered by some to be relatively late notice, it remains possible that the FDA will elect to organize such a meeting in conjunction with its review of the expanded label for Vascepa.

We estimate that our net product revenue for the three and six months ended June 30, 2019 are estimated to have reached between $97 and $101 million and between $170 and $174 million, respectively. These results represent an increase of approximately $44 to $48 million (approximately 84% to 92%) for the second quarter of 2019 over the corresponding period of 2018 and an increase of approximately $73 to $77 million (approximately 76% to 80%) for the first half of 2019 over the corresponding period of 2018. We estimate that, as of June 30, 2019, we had approximately $221 million in cash, approximately $94 million in net accounts receivable and approximately $47 million in inventory.

The information above is based on preliminary unaudited information and management estimates for the three and six months ended June 30, 2019, is not a comprehensive statement of our financial results, and is subject to completion of our financial closing procedures for such periods as well as the related external audit of the results of operations for the fiscal year ended December 31, 2019. This information should be read in conjunction with our consolidated financial statements and the related notes and “Management’s discussion and analysis of financial condition and results of operations” for prior periods in our public filings incorporated by reference into this prospectus. Our actual results for the three and six months ended June 30, 2019 and for the year ended December 31, 2019 will not be available until after this offering is completed, may differ materially from our preliminary estimates (including as a result of year-end closing and audit procedures and review adjustments) and are not necessarily indicative of the results to be expected for any future period. The information presented herein should not be considered a substitute for the financial information to be filed with the SEC in our Quarterly Report on Form 10-Q for the quarter ended June 30, 2019 and our Annual Report on Form 10-K for the fiscal year ended December 31, 2019 once it becomes available. Accordingly, you should not place undue reliance upon these preliminary estimates. There can be no assurance that these estimates will be realized, and estimates are subject to risks and uncertainties, many of which are not within our control. See the section entitled “Risk Factors” and “Special Note Regarding Forward-Looking Statements”. These preliminary estimates have been prepared by and are the responsibility of management. Our independent registered public accounting firm has not conducted a review of, and does not express an opinion or any other form of assurance with respect to, these preliminary estimates.

S-3

Risks related to our business

Our business and ability to execute our business strategy are subject to a number of risks of which you should be aware before you decide to buy our ADSs. In particular, you should consider the following risks, which are discussed more fully in the section entitled “Risk Factors” in this prospectus supplement and in our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2019, which are incorporated herein by reference:

• We are substantially dependent upon sales of Vascepa in the United States.

• A failure to obtain an expanded label may make it more difficult for Vascepa to gain market acceptance by physicians, patients, healthcare payors and others in the medical community necessary for commercial success.

• Our SPA agreement for REDUCE-IT is not a guarantee of FDA approval of Vascepa for proposed REDUCE-IT indications, as evidenced by our SPA agreement for ANCHOR having been previously rescinded.

• Our products and marketing efforts are subject to extensive post-approval government regulation.

• We are dependent on patents, proprietary rights and confidentiality to protect the commercial potential of Vascepa.

• Although we began generating revenue from Vascepa in January 2013, we may never be profitable and we intend to increase our spending levels, particularly for commercialization of Vascepa assuming an expanded label.

Corporation information

Amarin Corporation plc (formerly Ethical Holdings plc) is a public limited company listed in the United States on The Nasdaq Global Market. Amarin was originally incorporated in England as a private limited company on March 1, 1989 under the Companies Act 1985, and re-registered in England as a public limited company on March 19, 1993. Our registered office is located at One New Change, London EC4M 9AF, England. Our principal executive offices are located at 77 Sir John Rogerson’s Quay, Block C, Grand Canal Docklands, Dublin 2, Ireland and our telephone number is +353-1-6699-020. Our primary U.S. offices are located at 1430 Route 206, Bedminster, NJ 07921.

S-4

The offering

ADSs offered by us 22,222,223 ADSs

Option to purchase additional ADSs We have granted the underwriters an option for a period of 30 days to purchase up to 3,333,333 additional ADSs.

Ordinary shares to be outstanding after this offering 352,800,391 shares (356,133,724 shares if the underwriters exercise in full their option to purchase additional ADSs)

Use of proceeds

We intend to use the net proceeds from this offering (1) to support the ongoing and expanding commercialization of Vascepa assuming the FDA approves our proposed label expansion, including (i) doubling the size of our existing sales force, (ii) increasing branded and non-branded advertising, and (iii) supporting our expanded commercial operations; (2) to increase commercial supply of Vascepa from third-party drug product suppliers; and (3) for general corporate purposes. We also may use a portion of the net proceeds to acquire strategic assets, although we currently have no agreements or commitments in this regard. See “Use of Proceeds.”

Risk factors

This investment involves a high degree of risk. See the information contained in or incorporated by reference under “Risk Factors” beginning on page S-9 of this prospectus supplement and in the documents incorporated by reference into this prospectus supplement.

NASDAQ global market symbol

“AMRN”

The number of ordinary shares to be outstanding after this offering is based on 330,578,168 ordinary shares outstanding on March 31, 2019, and excludes as of that date:

• 16,837,051 ADSs, each ADS representing one ordinary share, issuable upon exercise of outstanding options, at a weighted average exercise price of $5.51 per share, issuable under our 2002 Stock Option Plan and 2011 Stock Incentive Plan, or the Plans, and other equity incentive plans;

• 9,341,393 ADSs, each ADS representing one ordinary share, reserved for issuance in connection with restricted stock units issued under our Plans;

• 8,925,645 ADSs, each ADS representing one ordinary share, available for grant under our 2011 Stock Incentive Plan;

• 2,687,743 ADSs, each ADS representing one ordinary share, available for grant under our 2017 Employee Stock Purchase Plan; and

S-5

• 28,931,746 ADSs, each ADS representing one ordinary share, currently issuable upon the consolidation and redesignation of 289,317,460 outstanding Series A Preference Shares into ordinary shares at a ratio of 10 preference shares for 1 ordinary share.

If the underwriters’ option is exercised in full, we will issue and sell an additional 3,333,333 our ADSs and will have 356,133,724 ordinary shares outstanding after the offering.

Except as otherwise indicated, all information in this prospectus supplement assumes no exercise by the underwriters of their option.

S-6

Cautionary statement regarding forward-looking statements

This prospectus supplement, the accompanying prospectus and the documents incorporated by reference herein and therein contain express or implied forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. Forward-looking statements relate to future events or our future financial performance. We generally identify forward-looking statements by terminology such as “may,” “will,” “would,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “contemplates,” “believes,” “estimates,” “predicts,” “assume,” “intend,” “potential,” “continue” or other similar words or the negative of these terms. These statements are only predictions. Accordingly, these statements involve estimates, assumptions and uncertainties which could cause actual results to differ materially from those expressed in them. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. The outcome of the events described in these forward-looking statements is subject to risks, uncertainties and other factors described in “Risk Factors” and in our periodic filings with the SEC, incorporated by reference or included in this prospectus supplement and the accompanying prospectus. Accordingly, you should not place undue reliance upon these forward-looking statements. We cannot assure you that the events and circumstances reflected in the forward-looking statements will be achieved or occur, the timing of events and circumstances and actual results could differ materially from those projected in the forward-looking statements. Forward-looking statements contained herein include, but are not limited to, statements about:

• our expectations related to the use of proceeds from this offering;

• our ability to maintain sufficient cash and other liquid resources to meet our operating requirements;

• decisions by regulatory authorities with respect to our pending and approved applications, in particular as it relates to our initial product Vascepa;

• the interpretation of and regulatory developments relating to the final results from our REDUCE-IT outcomes study;

• decisions by regulatory authorities regarding whether and when to approve our drug applications as well as their decisions regarding labeling and other matters that could affect the commercial potential of our products;

• levels of future commercial sales of Vascepa;

• additional regulatory scrutiny from our promotion of Vascepa;

• the success with which developed products may be commercialized, in particular our ability to continue to execute, through our recently hired sales force or otherwise, the commercial launch of Vascepa;

• the timing of communications with the FDA;

• whether and when we will be able to enter into and consummate strategic collaborations with respect to our products or product candidates on acceptable terms;

• the speed with which regulatory authorizations, regulatory exclusivity decisions and pricing approvals and product launches may be achieved;

• the success of our research and development activities;

• the safety and efficacy of our products and product candidates;

S-7

• the propensity of clinicians to prescribe our products to approved patient populations;

• estimates of the potential markets for our products and product candidates, including the cost-effectiveness of such products;

• estimates regarding our financial results;

• our expectations reading the qualification of additional third-party manufacturing suppliers and estimates of the capacity of manufacturing and other facilities to support our products;

• competitive developments affecting our products or product candidates, including generic and branded competition;

• the scope of our intellectual property protection and the likelihood of securing additional patent protection;

• our ability to protect our patents and other intellectual property;

• the effect of possible domestic and foreign legislation or regulatory action affecting, among other things, pharmaceutical pricing and reimbursement, including under Medicaid and Medicare in the United States, and involuntary approval of prescription medicines for over-the-counter use and the trend toward managed care and health care cost containment;

• claims and concerns that may arise regarding the safety or efficacy of our products or product candidates;

• governmental laws and regulations affecting our operations, including those affecting taxation;

• growth in costs and expenses; and

• other risks and uncertainties, including those listed under the caption entitled “Risk Factors.”

The forward-looking statements made or incorporated by reference herein relate only to events as of the date on which the statements are made. We have included important factors in the cautionary statements included herein and incorporated herein by reference, including under the caption entitled “Risk Factors” that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make. Except as required by law, we do not assume any intent to update any forward-looking statements after the date on which the statement is made, whether as a result of new information, future events or circumstances or otherwise. You should read this prospectus, together with the documents that we have filed with the SEC that are incorporated by reference and any free writing prospectus we have authorized for use in connection with a specific offering, completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of the forward-looking statements in this prospectus by these cautionary statements.

S-8

Risk factors

An investment in our ADSs and our ordinary shares involves a high degree of risk. Before deciding whether to invest in our ADSs and our ordinary shares, you should consider carefully the risks described below, together with other information in this prospectus supplement, the accompanying prospectus and the information and documents incorporated by reference in this prospectus supplement and the accompanying prospectus, including (i) our most recent quarterly report on Form 10-Q for the quarter ended March 31, 2019 which is on file with the SEC and is incorporated herein by reference and (ii) other documents we file with the SEC (including Current Reports on Form 8-K) that are deemed incorporated by reference into this prospectus supplement. Any of these risks could seriously harm our business, financial condition, results of operations or cash flow, resulting in the decline of the trading price of our ADSs and a loss of all or part of your investment.

Risks related to this offering

Management will have broad discretion as to the use of the proceeds from this offering, and we may not use the proceeds effectively.

We have not designated the amount of net proceeds we will use for any particular purpose. Accordingly, our management will have broad discretion as to the application of the net proceeds and could use them for purposes other than those contemplated at the time of this offering. Our shareholders may not agree with the manner in which our management chooses to allocate and spend the net proceeds. Moreover, our management may use the net proceeds for corporate purposes that may not increase our profitability or our market value. See “Use of Proceeds” for a description of our management’s intended use of the proceeds from this offering.

You will experience immediate dilution in the book value per share of the ADSs you purchase.

Because the price per share of our ADSs being offered is substantially higher than the book value per share of our ADSs, you will suffer substantial dilution in the net tangible book value of the ADSs you purchase in this offering. Based on the public offering price of $18.00 per ADS, if you purchase ADSs in this offering, you will suffer immediate and substantial dilution of $16.54 per ADS compared to the net tangible book value of the ADSs as of March 31, 2019. To the extent outstanding options and other securities are exercised or converted into ordinary shares or ADSs, you will experience significant additional dilution. See “Dilution” for a more detailed discussion of the dilution you will incur in this offering.

Risks related to our business

If FDA decides to hold an advisory committee meeting in connection with our sNDA for the REDUCE-IT indication, data interpretations or other information from FDA or the committee could be made public that are negative or may delay approval or limit Vascepa’s marketability.

The FDA is not required to inform sponsor companies that it does not intend to hold an AdCom. As of the date of this Preliminary Prospectus Supplement, the FDA has not informed Amarin whether it plans to hold an AdCom meeting to discuss our sNDA seeking an expanded indication for Vascepa in the United States based on the results of the REDUCE-IT study, nor has the FDA informed us of the subject matter intended to be the focus of a potential AdCom meeting if one were to be scheduled. While such notification now would be considered by some to be relatively late notice, it remains possible that the FDA will elect to organize such a meeting in conjunction with its review of the expanded label for Vascepa. In the event that the FDA informs us that it plans to hold an AdCom meeting in connection with our sNDA, the FDA will publish on its website shortly before the AdCom meeting a briefing book that includes questions for committee consideration and the agency’s evaluation of data and issues relevant to FDA’s review of the sNDA. The briefing book may identify concerns the

S-9

agency has with our sNDA that differ from public expectations. Even if the AdCom ultimately disagrees with agency concerns, the publication of concerns from FDA and the degree to which the public views agency concerns as material to, for example, the prospects and scope of approval of the sNDA, may negatively affect us. The FDA is not bound by the recommendations of an advisory committee, which is typically composed of clinicians, statisticians and other experts, but it generally follows such recommendations. In addition, the AdCom may recommend against approval of our application or may recommend that the FDA require, as a condition of approval or as a post-approval commitment, additional preclinical studies or clinical trials. This may delay and increase the cost of the review and approval process. Although not typically the case, the FDA can also, at its option, delay the target date for completion of our sNDA to allow for additional time for an advisory committee meeting or to, for example, provide more time to assess new or existing information in connection with the sNDA review. Any delay in obtaining, or an inability to obtain, expanded marketing approval could prevent us from commercializing Vascepa in the REDUCE-IT indication, generating revenue at current or increasing rates of growth, and achieving profitability, any of which could materially harm our business and cause our stock price to decline.

Our internal computer systems, or those of our third-party clinical research organizations or other contractors or consultants, may fail or suffer security breaches, which could result in a material disruption of our research and development programs.

Despite the implementation of security measures, our internal computer systems and those of our third-party clinical research organizations and other contractors and consultants are vulnerable to damage from computer viruses, unauthorized access, natural disasters, terrorism, war, and telecommunication and electrical failures. Any such incident could cause interruptions in our operations or a material disruption of our programs. To the extent that any disruption or security breach results in a loss of or damage to our data or applications or other data or applications relating to our technology or products candidates, or inappropriate disclosure of confidential or proprietary information, we could incur liabilities and our research and development program could be delayed.

We could be subject to risks caused by misappropriation, misuse, leakage, falsification or intentional or accidental release or loss of information maintained in the information systems and networks of our company and our vendors, including personal information of our employees and patients, and company and vendor confidential data. In addition, outside parties may attempt to penetrate our systems or those of our vendors or fraudulently induce our personnel or the personnel of our vendors to disclose sensitive information in order to gain access to our data and/or systems. We may experience threats to our data and systems, including malicious codes and viruses, phishing and other cyber-attacks. The number and complexity of these threats continue to increase over time. For instance, in June 2019, a report published by security researchers claimed that a database, which we are informed did not include social security numbers or credit card information, belonging to one of our vendors containing information about individuals who use or have expressed interest in Vascepa was accessible to unauthorized users. If a material breach of our information technology systems or those of our vendors occurs, the market perception of the effectiveness of our security measures could be harmed and our reputation and credibility could be damaged. We could be required to expend significant amounts of money and other resources to repair or replace information systems or networks and to repair reputational costs. In addition, we could be subject to regulatory actions and/or claims made by individuals and groups in private litigation involving privacy issues related to data collection and use practices and other data privacy laws and regulations, including claims for misuse or inappropriate disclosure of data, as well as unfair or deceptive practices. We may incur significant costs or divert significant internal resources as a result of any regulatory actions or private litigation. Any of the foregoing consequences may adversely affect our business and financial condition.

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Although we develop and maintain systems and controls designed to prevent these events from occurring, and we have a process to identify and mitigate threats, the development and maintenance of these systems, controls and processes is costly and requires ongoing monitoring and updating as technologies change and efforts to overcome security measures become increasingly sophisticated. Moreover, despite our efforts, the possibility of these events occurring cannot be eliminated entirely. As we outsource more of our information systems to vendors, engage in more electronic transactions with payors and patients, and rely more on cloud-based information systems, the related security risks will increase and we will need to expend additional resources to protect our technology and information systems. In addition, there can be no assurance that our internal information technology systems or those of our third-party contractors, or our consultants’ efforts to implement adequate security and control measures, will be sufficient to protect us against breakdowns, service disruption, data deterioration or loss in the event of a system malfunction, or prevent data from being stolen or corrupted in the event of a cyberattack, security breach, industrial espionage attacks or insider threat attacks which could result in financial, legal, business or reputational harm.

Risks related to our financial position and capital requirements

We have a history of operating losses and anticipate that we will incur continued losses for an indefinite period of time.

We have not yet reached profitability. For the fiscal years ended December 31, 2018, 2017, and 2016, we reported losses of approximately $116.4 million, $67.9 million, and $86.4 million, respectively, and we had an accumulated deficit as of December 31, 2018 of $1.4 billion. Substantially all of our operating losses resulted from costs incurred in connection with our research and development programs, from general and administrative costs associated with our operations, and costs related to the commercialization of Vascepa. Additionally, as a result of our significant expenses relating to research and development and to commercialization, we expect to continue to incur significant operating losses for an indefinite period. Because of the numerous risks and uncertainties associated with developing and commercializing pharmaceutical products, we are unable to predict the magnitude of these future losses. Our historic losses, combined with expected future losses, have had and will continue to have an adverse effect on our cash resources, shareholders’ deficit and working capital.

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Description of American Depositary Shares

Citibank, N.A. has agreed to act as the depositary bank for the American Depositary Shares. Citibank’s depositary offices are located at 388 Greenwich Street, New York, New York 10013. American Depositary Shares are frequently referred to as “ADSs” and represent ownership interests in securities that are on deposit with the depositary bank. ADSs may be represented by certificates that are commonly known as “American Depositary Receipts” or “ADRs.” The depositary bank typically appoints a custodian to safekeep the securities on deposit. In this case, the custodian is Citibank, N.A., London Branch, having its principal office at Citigroup Centre, Canada Square, Canary Wharf, London E14 5LB, England.

We have appointed Citibank as depositary bank pursuant to an amended and restated deposit agreement as of November 4, 2011. A copy of the deposit agreement is on file with the SEC under cover of a Registration Statement on Form F-6 filed on September 16, 2011. You may obtain a copy of the deposit agreement from the SEC’s website (www.sec.gov). Please refer to Registration Number 333-176898 when retrieving such copy.

We are providing you with a summary description of the material terms of the ADSs and of your material rights as an owner of ADSs. Please remember that summaries by their nature lack the precision of the information summarized and that the rights and obligations of an owner of ADSs will be determined by reference to the terms of the deposit agreement and not by this summary. We urge you to review the deposit agreement in its entirety.

Each ADS represents the right to receive one ordinary share on deposit with the custodian. An ADS also represents the right to receive any other property received by the depositary bank or the custodian on behalf of the owner of the ADS but that has not been distributed to the owners of ADSs because of legal restrictions or practical considerations. The custodian, the depositary bank and their respective nominees will hold all deposited property for the benefit of the holders and beneficial owners of ADSs. The deposited property does not constitute the proprietary assets of the depositary bank, the custodian or their nominees. Beneficial ownership in the deposited property will under the terms of the deposit agreement be vested in the beneficial owners of the ADSs. The depositary bank, the custodian and their respective nominees will be the record holders of the deposited property represented by the ADSs for the benefit of the holders and beneficial owners of the corresponding ADSs. Owners of ADSs will be able to exercise beneficial ownership interests in the deposited property only through the registered holders of the ADSs, by the registered holders of the ADSs (on behalf of the applicable ADS owners) only through the depositary bank, and by the depositary bank (on behalf of the owners of the corresponding ADSs) directly, or indirectly through the custodian or their respective nominees, in each case upon the terms of the deposit agreement.

If you become an owner of ADSs, you will become a party to the deposit agreement and therefore will be bound to its terms and to the terms of any ADR that represents your ADSs. The deposit agreement and the ADR specify our rights and obligations as well as your rights and obligations as owner of ADSs and those of the depositary bank. As an ADS holder you appoint the depositary bank to act on your behalf in certain circumstances. The deposit agreement and the ADRs are governed by New York law. However, our obligations to the holders of ordinary shares will continue to be governed by the laws of England and Wales, which may be different from the laws in the United States.

As an owner of ADSs, you may hold your ADSs either by means of an ADR registered in your name, through a brokerage or safekeeping account, or through an account established by the depositary bank in your name reflecting the registration of uncertificated ADSs directly on the books of the depositary bank (commonly referred to as the “direct registration system” or “DRS”). The direct registration system reflects the uncertificated (book-entry) registration of ownership of ADSs by the depositary bank. Under the direct registration system, ownership of ADSs is evidenced by periodic statements issued by the depositary bank to

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the holders of the ADSs. The direct registration system includes automated transfers between the depositary bank and The Depository Trust Company, or DTC, the central book-entry clearing and settlement system for equity securities in the United States. If you decide to hold your ADSs through your brokerage or safekeeping account, you must rely on the procedures of your broker or bank to assert your rights as ADS owner. Banks and brokers typically hold securities such as the ADSs through clearing and settlement systems such as DTC. The procedures of such clearing and settlement systems may limit your ability to exercise your rights as an owner of ADSs. Please consult with your broker or bank if you have any questions concerning these limitations and procedures. All ADSs held through DTC will be registered in the name of a nominee of DTC. This summary description assumes you have opted to own the ADSs directly by means of an ADS registered in your name and, as such, we will refer to you as the “holder.” When we refer to “you,” we assume the reader owns ADSs and will own ADSs at the relevant time.

Dividends and distributions

As a holder of ADSs, you generally have the right to receive the distributions we make on the securities deposited with the custodian. Your receipt of these distributions may be limited, however, by practical considerations and legal limitations. Holders of ADSs will receive such distributions under the terms of the deposit agreement in proportion to the number of ADSs held as of a specified record date, after deduction the applicable fees, taxes and expenses.

Distributions of cash

Whenever we make a cash distribution for the securities on deposit with the custodian, we will deposit the funds with the custodian. Upon receipt of confirmation of the deposit of the requisite funds, the depositary bank will arrange for the funds to be converted into U.S. dollars and for the distribution of the U.S. dollars to the holders, subject to English laws and regulations.

The conversion into U.S. dollars will take place only if practicable and if the U.S. dollars are transferable to the United States. The depositary bank will apply the same method for distributing the proceeds of the sale of any property (such as undistributed rights) held by the custodian in respect of securities on deposit.

The distribution of cash will be made net of the fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. The depositary bank will hold any cash amounts it is unable to distribute in a non-interest bearing account for the benefit of the applicable holders and beneficial owners of ADSs until the distribution can be effected or the funds that the depositary bank holds must be escheated as unclaimed property in accordance with the laws of the relevant states of the United States.

Distributions of shares

Whenever we make a free distribution of shares for the securities on deposit with the custodian, we will deposit the applicable number of shares with the custodian. Upon receipt of confirmation of such deposit, the depositary bank will either distribute to holders new ADSs representing the ordinary shares deposited or modify the ADS-to-shares ratio, in which case each ADS you hold will represent rights and interests in the additional ordinary shares or preference shares so deposited. Only whole new ADSs will be distributed. Fractional entitlements will be sold and the proceeds of such sale will be distributed as in the case of a cash distribution.

The distribution of new ADSs or the modification of the ADS-to-ordinary shares ratio upon a distribution of ordinary shares or preference shares will be made net of the fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. In order to pay such taxes or governmental

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charges, the depositary bank may sell all or a portion of the new ordinary shares so distributed. No such distribution of new ADSs will be made if it would violate a law (i.e., the U.S. securities laws) or if it is not operationally practicable. If the depositary bank does not distribute new ADSs as described above, it may sell the shares received upon the terms described in the deposit agreement and will distribute the proceeds of the sale as in the case of a distribution of cash.

Distributions of rights

Whenever we intend to distribute rights to purchase additional ordinary shares, we will give prior notice to the depositary bank and we will assist the depositary bank in determining whether it is lawful and reasonably practicable to distribute rights to purchase additional ADSs to holders.

The depositary bank will establish procedures to distribute rights to purchase additional ADSs to holders and to enable such holders to exercise such rights if it is lawful and reasonably practicable to make the rights available to holders of ADSs, and if we provide all of the documentation contemplated in the deposit agreement (such as opinions to address the lawfulness of the transaction). You may have to pay fees, expenses, taxes and other governmental charges to subscribe for the new ADSs upon the exercise of your rights. The depositary bank is not obligated to establish procedures to facilitate the distribution and exercise by holders of rights to purchase new ordinary shares other than in the form of ADSs.

The depositary bank will not distribute the rights to you if:

• we do not timely request that the rights be distributed to you or we request that the rights not be distributed to you; or

• we fail to deliver satisfactory documents to the depositary bank; or

• it is not reasonably practicable to distribute the rights.

The depositary bank will sell the rights that are not exercised or not distributed if such sale is lawful and reasonably practicable. The proceeds of such sale will be distributed to holders as in the case of a cash distribution. If the depositary bank is unable to sell the rights, it will allow the rights to lapse.

Elective distributions

Whenever we intend to distribute a dividend payable at the election of shareholders either in cash or in additional shares, we will give prior notice thereof to the depositary bank and will indicate whether we wish the elective distribution to be made available to you. In such case, we will assist the depositary bank in determining whether such distribution is lawful and reasonably practicable.

The depositary bank will make the election available to you only if it is reasonably practicable and if we have provided all of the documentation contemplated in the deposit agreement. In such case, the depositary bank will establish procedures to enable you to elect to receive either cash or additional ADSs, in each case as described in the deposit agreement.

If the election is not made available to you, you will receive either cash or additional ADSs, depending on what a shareholder under English law would receive upon failing to make an election, as more fully described in the deposit agreement.

Other distributions

Whenever we intend to distribute property other than cash, ordinary shares or rights to purchase additional ordinary shares, we will notify the depositary bank in advance and will indicate whether we wish such

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distribution to be made to you. If so, we will assist the depositary bank in determining whether such distribution to holders is lawful and reasonably practicable. If it is reasonably practicable to distribute such property to you and if we provide all of the documentation contemplated in the deposit agreement, the depositary bank will distribute the property to the holders in a manner it deems practicable.

The distribution will be made net of fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. In order to pay such taxes and governmental charges, the depositary bank may sell all or a portion of the property received.

The depositary bank will not distribute the property to you and will sell the property if:

• we do not request that the property be distributed to you or if we ask that the property not be distributed to you; or

• we do not deliver satisfactory documents to the depositary bank; or

• the depositary bank determines that all or a portion of the distribution to you is not reasonably practicable.

The proceeds of such a sale will be distributed to holders as in the case of a cash distribution.

Redemption

Whenever we decide to redeem any of the securities on deposit with the custodian, we will notify the depositary bank in advance. If it is practicable and if we provide all of the documentation contemplated in the deposit agreement, the depositary bank will provide notice of the redemption to the holders.

The custodian will be instructed to surrender the shares being redeemed against payment of the applicable redemption price. The depositary bank will convert the redemption funds received into U.S. dollars upon the terms of the deposit agreement and will establish procedures to enable holders to receive the net proceeds from the redemption upon surrender of their ADSs to the depositary bank. You may have to pay fees, expenses, taxes and other governmental charges upon the redemption of your ADSs. If less than all ADSs are being redeemed, the ADSs to be retired will be selected by lot or on a pro rata basis, as the depositary bank may determine.

Changes affecting ordinary shares and preference shares

The ordinary shares held on deposit for your ADSs may change from time to time. For example, there may be a change in nominal or par value, a split-up, cancellation, consolidation or reclassification of such ordinary shares or a recapitalization, reorganization, merger, consolidation or sale of assets.

If any such change were to occur, your ADSs would, to the extent permitted by law, represent the right to receive the property received or exchanged in respect of the new ordinary shares held on deposit. The depositary bank may in such circumstances deliver new ADSs to you, amend the deposit agreement, the ADRs and the applicable Registration Statement(s) on Form F-6, call for the exchange of your existing ADSs for new ADSs and take any other actions that are appropriate to reflect as to the ADSs the change affecting the Shares. If the depositary bank may not lawfully distribute such property to you, the depositary bank may sell such property and distribute the net proceeds to you as in the case of a cash distribution.

Issuance of ADSs upon deposit of ordinary shares

Upon completion of this offering, the ordinary shares being offered pursuant to this prospectus will be deposited by us with the custodian. Upon receipt of confirmation of such deposit, the depositary bank will issue ADSs to the underwriters named in this prospectus.

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After the closing of this offer, the depositary bank may create ADSs on your behalf if you or your broker deposit ordinary shares with the custodian. The depositary bank will deliver these ADSs to the person you indicate only after you pay any applicable issuance fees and any charges and taxes payable for the transfer of the ordinary shares to the custodian. Your ability to deposit ordinary shares and receive ADSs may be limited by U.S. and U.K. legal considerations applicable at the time of deposit.

The issuance of ADSs may be delayed until the depositary bank or the custodian receives confirmation that all required approvals have been given and that the ordinary shares or preference shares have been duly transferred to the custodian. The depositary bank will only issue ADSs in whole numbers.

When you make a deposit of ordinary shares you will be responsible for transferring good and valid title to the depositary bank. As such, you will be deemed to represent and warrant that:

• the ordinary shares are duly authorized, validly issued, fully paid, non-assessable and legally obtained;

• all preemptive (and similar) rights, if any, with respect to such ordinary shares have been validly waived or exercised;

• you are duly authorized to deposit the ordinary shares;

• the ordinary shares presented for deposit are free and clear of any lien, encumbrance, security interest, charge, mortgage or adverse claim, and the ADSs issuable upon such deposit will not be, “restricted securities” (as defined in the deposit agreement); and

• the ordinary shares presented for deposit have not been stripped of any rights or entitlements.

If any of the representations or warranties are incorrect in any way, we and the depositary bank may, at your cost and expense, take any and all actions necessary to correct the consequences of the misrepresentations.

Transfer, combination and split up of ADRs

As an ADR holder, you will be entitled to transfer, combine or split up your ADRs and the ADSs evidenced thereby. For transfers of ADRs, you will have to surrender the ADRs to be transferred to the depositary bank and also must:

• ensure that the surrendered ADR is properly endorsed or otherwise in proper form for transfer;

• provide such proof of identity and genuineness of signatures as the depositary bank deems appropriate;

• provide any transfer stamps required by the State of New York or the United States; and

• pay all applicable fees, charges, expenses, taxes and other government charges payable by ADR holders pursuant to the terms of the deposit agreement, upon the transfer of ADRs.

To have your ADRs either combined or split up, you must surrender the ADRs in question to the depositary bank with your request to have them combined or split up, and you must pay all applicable fees, charges and expenses payable by ADR holders, pursuant to the terms of the deposit agreement, upon a combination or split up of ADRs.

Withdrawal of ordinary shares upon cancellation of ADSs

As an ADS holder, you will be entitled to present your ADSs to the depositary bank for cancellation and then receive the corresponding number of underlying ordinary shares at the custodian’s offices. Your ability to

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withdraw the ordinary shares may be limited by U.S. and U.K. legal considerations applicable at the time of withdrawal. In order to withdraw the ordinary shares represented by your ADSs, you will be required to pay to the depositary bank the fees for cancellation of ADSs and any charges and taxes payable upon the transfer of the ordinary shares being withdrawn. You assume the risk for delivery of all funds and securities upon withdrawal. Once canceled, the ADSs will not have any rights under the deposit agreement.

If you hold ADSs registered in your name, the depositary bank may ask you to provide proof of identity and genuineness of any signature and such other documents as the depositary bank may deem appropriate before it will cancel your ADSs. The withdrawal of the ordinary shares represented by your ADSs may be delayed until the depositary bank receives satisfactory evidence of compliance with all applicable laws and regulations. Please keep in mind that the depositary bank will only accept ADSs for cancellation that represent a whole number of securities on deposit.

You will have the right to withdraw the securities represented by your ADSs at any time except for:

• Temporary delays that may arise because (i) the transfer books for the ordinary shares or ADSs are closed, or (ii) ordinary shares are immobilized on account of a shareholders’ meeting or a payment of dividends.

• Outstanding obligations to pay fees, taxes and similar charges.

• Restrictions imposed because of laws or regulations applicable to ADSs or the withdrawal of securities on deposit.

The deposit agreement may not be modified to impair your right to withdraw the securities represented by your ADSs except to comply with mandatory provisions of law.

Voting rights

As a holder of ADSs representing ordinary shares, you generally have the right under the deposit agreement to instruct the depositary bank to exercise the voting rights for the ordinary shares represented by your ADSs. The voting rights of holders of ordinary shares are described under the heading “Description of Securities—Description of Ordinary Shares” in this prospectus.

At our request, the depositary bank will distribute to you any notice of shareholders’ meeting received from us together with information explaining how to instruct the depositary bank to exercise the voting rights of the securities represented by ADSs.

If the depositary bank timely receives voting instructions from a holder of ADSs, it will endeavor to vote the securities (in person or by proxy) represented by the holder’s ADSs in accordance with such voting instructions.

Please note that the ability of the depositary bank to carry out voting instructions may be limited by practical and legal limitations and the terms of the securities on deposit. We cannot assure you that you will receive voting materials in time to enable you to return voting instructions to the depositary bank in a timely manner. Securities for which no voting instructions have been received will not be voted.

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Fees and charges

As an ADS holder, you will be required to pay the following service fees to the depositary bank:

Service	Fees
•  Issuance of ADSs upon deposit of Shares (excluding issuances as a result of distributions described in paragraph (4) below).	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) issued.
•  Delivery of Deposited Securities against surrender of ADSs.	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) surrendered.
•  Distribution of cash dividends or other cash distributions (i.e., sale of rights and other entitlements).	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) held.
•  Distribution of ADSs pursuant to (i) stock dividends or other free stock distributions, or (ii) exercise of rights to purchase additional ADSs.	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) held.
•  Distribution of securities other than ADSs or rights to purchase additional ADSs (i.e., spin-off shares).	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) held.
•  Depositary Services.	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) held on the applicable record date(s) established by the Depositary.

As an ADS holder you will also be responsible to pay certain fees and expenses incurred by the depositary bank and certain taxes and governmental charges such as:

• Fees for the transfer and registration of ordinary shares charged by the registrar and transfer agent for the ordinary shares or preference shares in England (i.e., upon deposit and withdrawal of ordinary shares or preference shares).

• Expenses incurred for converting foreign currency into U.S. dollars.

• Expenses for cable, telex and fax transmissions and for delivery of securities.

• Taxes and duties upon the transfer of securities (i.e., when ordinary shares are deposited or withdrawn from deposit).

• Fees and expenses incurred in connection with the delivery or servicing of ordinary shares on deposit.

Depositary fees payable upon the issuance and cancellation of ADSs are typically paid to the depositary bank by the brokers (on behalf of their clients) receiving the newly issued ADSs from the depositary bank and by the brokers (on behalf of their clients) delivering the ADSs to the depositary bank for cancellation. The brokers in turn charge these fees to their clients. Depositary fees payable in connection with distributions of cash or securities to ADS holders and the depositary services fee are charged by the depositary bank to the holders of record of ADSs as of the applicable ADS record date.

The Depositary fees payable for cash distributions are generally deducted from the cash being distributed. In the case of distributions other than cash (i.e., stock dividend, rights), the depositary bank charges the applicable fee to the ADS record date holders concurrent with the distribution. In the case of ADSs registered in the name of the investor (whether certificated or uncertificated in direct registration), the depositary bank

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sends invoices to the applicable record date ADS holders. In the case of ADSs held in brokerage and custodian accounts (via DTC), the depositary bank generally collects its fees through the systems provided by DTC (whose nominee is the registered holder of the ADSs held in DTC) from the brokers and custodians holding ADSs in their DTC accounts. The brokers and custodians who hold their clients’ ADSs in DTC accounts in turn charge their clients’ accounts the amount of the fees paid to the depositary banks.

In the event of refusal to pay the depositary fees, the depositary bank may, under the terms of the deposit agreement, refuse the requested service until payment is received or may set off the amount of the depositary fees from any distribution to be made to the ADS holder.

Note that the fees and charges you may be required to pay may vary over time and may be changed by us and by the depositary bank. You will receive prior notice of such changes.

The depositary bank may reimburse us for certain expenses incurred by us in respect of the ADR program established pursuant to the deposit agreement, by making available a portion of the depositary fees charged in respect of the ADR program or otherwise, upon such terms and conditions as we and the depositary bank may agree from time to time.

Amendments and termination

We may agree with the depositary bank to modify the deposit agreement at any time without your consent. We undertake to give holders 30 days’ prior notice of any modifications that would materially prejudice any of their substantial rights under the deposit agreement. We will not consider to be materially prejudicial to your substantial rights any modifications or supplements that are reasonably necessary for the ADSs to be registered under the Securities Act or to be eligible for book-entry settlement, in each case without imposing or increasing the fees and charges you are required to pay. In addition, we may not be able to provide you with prior notice of any modifications or supplements that are required to accommodate compliance with applicable provisions of law.

You will be bound by the modifications to the deposit agreement if you continue to hold your ADSs after the modifications to the deposit agreement become effective. The deposit agreement cannot be amended to prevent you from withdrawing the ordinary shares represented by your ADSs (except in order to comply with applicable by law).

We have the right to direct the depositary bank to terminate the deposit agreement. Similarly, the depositary bank may in certain circumstances on its own initiative terminate the deposit agreement. In either case, the depositary bank must give notice to the holders at least 30 days before termination. Until termination, your rights under the deposit agreement will be unaffected.

After termination, the depositary bank will continue to collect distributions received (but will not distribute any such property until you request the cancellation of your ADSs) and may sell the securities held on deposit. After the sale, the depositary bank will hold the proceeds from such sale and any other funds then held for the holders of ADSs in a non-interest bearing account. At that point, the depositary bank will have no further obligations to holders other than to account for the funds then held for the holders of ADSs still outstanding (after deduction of applicable fees, taxes and expenses).

Books of depositary

The depositary bank will maintain ADS holder records at its depositary office. You may inspect such records at such office during regular business hours but solely for the purpose of communicating with other holders in the interest of business matters relating to the ADSs and the deposit agreement.

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The depositary bank will maintain in New York facilities to record and process the issuance, cancellation, combination, split-up and transfer of ADSs. These facilities may be closed from time to time, to the extent not prohibited by law.

Limitations on obligations and liabilities

The deposit agreement limits our obligations and the depositary bank’s obligations to you. Please note the following:

• We and the depositary bank are obligated only to take the actions specifically stated in the deposit agreement without negligence or bad faith.

• The depositary bank disclaims any liability for any failure to carry out voting instructions, for any manner in which a vote is cast or for the effect of any vote, provided it acts in good faith and in accordance with the terms of the deposit agreement.

• The depositary bank disclaims any liability for any failure to determine the lawfulness or practicality of any action, for the content of any document forwarded to you on our behalf or for the accuracy of any translation of such a document, for the investment risks associated with investing in ordinary shares, for the validity or worth of the ordinary shares, for any tax consequences that result from the ownership of ADSs, for the credit-worthiness of any third party, for allowing any rights to lapse under the terms of the deposit agreement, for the timeliness of any of our notices or for our failure to give notice.

• We and the depositary bank will not be obligated to perform any act that is inconsistent with the terms of the deposit agreement.

• We and the depositary bank disclaim any liability if we or the depositary bank are prevented or forbidden from or subject to any civil or criminal penalty or restraint on account of, or delayed in, doing or performing any act or thing required by the terms of the deposit agreement, by reason of any provision, present or future of any law or regulation, or by reason of present or future provision of any provision of our Articles of Association, or any provision of or governing the securities on deposit, or by reason of any act of God or war or other circumstances beyond our control.

• We and the depositary bank disclaim any liability by reason of any exercise of, or failure to exercise, any discretion provided for in the deposit agreement or in our Articles of Association or in any provisions of or governing the securities on deposit.

• We and the depositary bank further disclaim any liability for any action or inaction in reliance on the advice or information received from legal counsel, accountants, any person presenting Shares for deposit, any holder of ADSs or authorized representatives thereof, or any other person believed by either of us in good faith to be competent to give such advice or information.

• We and the depositary bank also disclaim liability for the inability by a holder to benefit from any distribution, offering, right or other benefit that is made available to holders of ordinary shares but is not, under the terms of the deposit agreement, made available to you.

• We and the depositary bank may rely without any liability upon any written notice, request or other document believed to be genuine and to have been signed or presented by the proper parties.

• We and the depositary bank also disclaim liability for any consequential or punitive damages for any breach of the terms of the deposit agreement.

• No disclaimer of any Securities Act liability is intended by any provision of the deposit agreement.

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Pre-release transactions

Subject to the terms and conditions of the deposit agreement, the depositary may issue to broker/dealers ADSs before receiving a deposit of ordinary shares or release ordinary shares to broker/dealers before receiving ADSs for cancellation. These transactions are commonly referred to as “pre-release transactions,” and are entered into between the depositary bank and the applicable broker/dealer. The deposit agreement limits the aggregate size of pre-release transactions (not to exceed 30% of the number of ADSs outstanding) and imposes a number of conditions on such transactions (i.e., the need to receive collateral, the type of collateral required, the representations required from brokers, etc.). The depositary bank may retain the compensation received from the pre-release transactions.

Taxes

You will be responsible for the taxes and other governmental charges payable on the ADSs and the securities represented by the ADSs. We, the depositary bank and the custodian may deduct from any distribution the taxes and governmental charges payable by holders and may sell any and all property on deposit to pay the taxes and governmental charges payable by holders. You will be liable for any deficiency if the sale proceeds do not cover the taxes that are due.

The depositary bank may refuse to issue ADSs, to deliver, transfer, split and combine ADRs or to release securities on deposit until all taxes and charges are paid by the applicable holder. The depositary bank and the custodian may take reasonable administrative actions to obtain tax refunds and reduced tax withholding for any distributions on your behalf. However, you may be required to provide to the depositary bank and to the custodian proof of taxpayer status and residence and such other information as the depositary bank and the custodian may require to fulfill legal obligations. You are required to indemnify us, the depositary bank and the custodian for any claims with respect to taxes based on any tax benefit obtained for you.

Foreign currency conversion

The depositary bank will arrange for the conversion of all foreign currency received into U.S. dollars if such conversion is practical, and it will distribute the U.S. dollars in accordance with the terms of the deposit agreement. You may have to pay fees and expenses incurred in converting foreign currency, such as fees and expenses incurred in complying with currency exchange controls and other governmental requirements.

If the conversion of foreign currency is not practical or lawful, or if any required approvals are denied or not obtainable at a reasonable cost or within a reasonable period, the depositary bank may take the following actions in its discretion:

• Convert the foreign currency to the extent practical and lawful and distribute the U.S. dollars to the holders for whom the conversion and distribution is lawful and practical.

• Distribute the foreign currency to holders for whom the distribution is lawful and practical.

• Hold the foreign currency (without liability for interest) for the applicable holders.

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Use of proceeds

We estimate that the net proceeds from the sale of 22,222,223 ADSs that we are offering will be approximately $382.0 million, or approximately $439.5 million if the underwriters exercise in full their option to purchase 3,333,333 additional ADSs, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us. The underwriters have agreed to reimburse us for certain of our expenses in connection with this offering.

We intend to use the net proceeds from this offering (1) to support the ongoing and expanding commercialization of Vascepa assuming the FDA approves our proposed label expansion, including (i) doubling the size of our existing sales force, (ii) increasing branded and non-branded advertising, and (iii) supporting our expanded commercial operations; (2) to increase commercial supply of Vascepa from third-party drug product suppliers; and (3) for general corporate purposes. We also may use a portion of the net proceeds to acquire strategic assets, although we currently have no agreements or commitments in this regard.

The amounts and timing of these expenditures will depend on a number of factors, such as the continued growth of Vascepa revenue, the results of our expanded medical education and market awareness initiatives, amount of incremental inventory build, timing, scope, progress and results of our research and development efforts, whether Vascepa is approved in any additional indications, and the timing and progress of any partnering efforts. As of the date of this prospectus supplement, we cannot specify with certainty all of the particular uses of the proceeds from this offering. Accordingly, we will retain broad discretion over the use of such proceeds.

Our expected use of the net proceeds from this offering represents our current intentions based upon our present plans and business condition. As of the date of this prospectus, we cannot predict with certainty all of the particular uses for the net proceeds to be received upon the completion of this offering, or the amounts that we will actually spend on the uses set forth above. The amounts and timing of our actual use of the net proceeds will vary depending on numerous factors, including our ability to access additional financing, the relative success and cost of our research and development programs and commercialization efforts, and whether we are able to enter into future licensing arrangements. As a result, our management will have broad discretion in the application of the net proceeds, and investors will be relying on our judgment regarding the application of the net proceeds of this offering. In addition, we might decide to postpone, scale down or not pursue certain clinical or commercial activities if the net proceeds from this offering, and any other sources of cash are less than expected.

Until we use the net proceeds from this offering, we intend to invest the funds in short-term, investment-grade, interest-bearing securities.

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Dilution

Our net tangible book value as of March 31, 2019 was approximately $133.6 million, or $0.40 per ADS. Net tangible book value per ADS is determined by dividing our total tangible assets, less total liabilities, by the number of our ordinary shares outstanding as of March 31, 2019. Dilution in net tangible book value per ADS represents the difference between the amount per ADS paid by purchasers of ADSs in this offering and the net tangible book value per share of our ADSs immediately after this public offering.

After giving effect to the sale of 22,222,223 ADSs in this offering at the public offering price of $18.00 per ADS, after deducting the underwriting discounts and commissions and estimated offering expenses payable by us, our as adjusted net tangible book value as of March 31, 2019 would have been approximately $515.6 million, or $1.46 per ADS. This represents an immediate increase in net tangible book value of $1.06 per ADS to existing shareholders and immediate dilution in net tangible book value of $16.54 per ADS to investors purchasing our ADSs in this offering. The following table illustrates this dilution on a per ADS basis:

Public offering price per ADS			$	18.00
Net tangible book value per ADS as of March 31, 2019	$	0.40
Increase per ADS attributable to investors in this offering		1.06
As adjusted net tangible book value per ADS after this offering			$	1.46
Dilution per ADS to investors in this offering			$	16.54

If the underwriters exercise in full their option to purchase 3,333,333 additional ADSs at the public offering price of $18.00 per ADS, the as adjusted net tangible book value after this offering would be $1.61 per ADS, representing an increase in net tangible book value of $1.21 per ADS to existing shareholders and immediate dilution in net tangible book value of $16.39 per ADS to investors purchasing our ADSs in this offering.

The above discussion and table are based on 330,578,168 ordinary shares outstanding on March 31, 2019, and exclude as of that date:

• 16,837,051 ADSs, each ADS representing one ordinary share, issuable upon exercise of outstanding options, at a weighted average exercise price of $5.51 per share, issuable under our 2002 Stock Option Plan and 2011 Stock Incentive Plan, or the Plans, and other equity incentive plans;

• 9,341,393 ADSs, each ADS representing one ordinary share, reserved for issuance in connection with restricted stock units issued under our Plans;

• 8,925,645 ADSs, each ADS representing one ordinary share, available for grant under our 2011 Stock Incentive Plan;

• 2,687,743 ADSs, each ADS representing one ordinary share, available for grant under our 2017 Employee Stock Purchase Plan; and

• 28,931,746 ADSs, each ADS representing one ordinary share, currently issuable upon the consolidation and redesignation of 289,317,460 outstanding Series A Preference Shares into ordinary shares at a ratio of 10 preference shares for 1 ordinary share.

To the extent that outstanding options or other securities are exercised or converted into ordinary shares or ADSs, investors purchasing our ADSs in this offering will experience significant further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of these securities could result in further dilution to our shareholders.

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Certain U.K. tax considerations

Capital gains

If you are not resident in the United Kingdom (“UK”) for UK tax purposes, you will not be liable for UK tax on capital gains realized or accrued on the sale or other disposition of ordinary shares or ADSs unless the ordinary shares or ADSs are held in connection with your trade carried on in the UK through a branch or agency and the ordinary shares or ADSs are or have been used, held or acquired for the purposes of such trade or such branch or agency.

An individual holder of ordinary shares or ADSs who ceases to be resident in the UK for UK tax purposes for a period of less than 5 years and who disposes of ordinary shares or ADSs during that period may also be liable on returning to the UK for UK capital gains tax despite the fact that the individual may not be resident in the UK at the time of the disposal.

Inheritance tax

If you are an individual domiciled in the United States and are not a national of the UK for the purposes of the Inheritance and Gift Tax Treaty 1978 between the United States and the UK, any ordinary shares or ADS beneficially owned by you will not generally be subject to UK inheritance tax on your death or on a gift made by you during your lifetime, provided that any applicable United States federal gift or estate tax liability is paid, except where the ordinary share or ADS is part of the business property of your UK permanent establishment. Where the ordinary shares or ADSs have been placed in trust by a settlor who, at the time of the settlement, was domiciled in the United States and not a national of the UK, the ordinary shares or ADSs will not generally be subject to UK inheritance tax.

Stamp duty and stamp duty reserve tax

Transfer of ADSs and ADRs representing ADSs

No UK stamp duty or stamp duty reserve tax will be payable on an instrument transferring an ADS or an ADR representing an ADS or on a written agreement to transfer an ADS or an ADR representing an ADS whether made in or outside the UK.

Issue and transfer of ordinary shares

The issue of ordinary shares by Amarin will not give rise to a charge to UK stamp duty or stamp duty reserve tax. Transfers of ordinary shares, as opposed to ADSs or ADRs representing ADSs, will attract ad valorem stamp duty at the rate of 0.5% of the amount or value of the consideration (or in some circumstances, the open market value of those ordinary shares, if higher). A charge to stamp duty reserve tax, at the rate of 0.5% of the amount or value of the consideration (or in some circumstances, the open market value of the ordinary shares, if higher), will arise on an agreement to transfer ordinary shares. The stamp duty reserve tax is payable on the seventh day of the month following the month in which the charge arises. Where an instrument of transfer is executed and duly stamped before the expiry of a period of six years beginning with the date of that agreement, any stamp duty reserve tax that has not been paid ceases to be payable.

Taxation of dividends

Under UK law, there is no withholding tax on dividends paid on the ordinary shares or ADSs.

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Certain U.S. federal income tax considerations for U.S. holders

The following is a summary of certain U.S. federal income tax considerations with respect to the acquisition, ownership and disposition of ordinary shares or ADSs by a U.S. Holder (as defined below). This summary applies to you only if you hold ordinary shares or ADSs as a capital asset. This summary is based upon the U.S. Internal Revenue Code of 1986, as amended, which is referred to herein as the Code, regulations promulgated under the Code and administrative rulings and judicial decisions as in effect on the date of this prospectus, all of which are subject to change and to differing interpretations, possibly with retroactive effect, which could result in U.S. federal income tax considerations different from those summarized below.

This summary is general in nature and does not address the effects of any state or local taxes, the tax consequences in jurisdictions other than the United States or any U.S. federal taxes other than income tax (such as estate or gift tax). In addition, it does not address U.S. federal income tax consequences that may be relevant to you in your particular circumstances, including alternative minimum tax consequences, nor does it apply to you if you are a holder with a special status, such as:

• a person that owns, or is treated as owning under certain ownership attribution rules, 10% or more of the voting power or value of the stock of Amarin;

• a broker, dealer or trader in securities or currencies;

• a bank, mutual fund, life insurance company or other financial institution;

• a tax-exempt entity;

• a qualified retirement plan or individual retirement account;

• a person that holds ordinary shares or ADSs as part of a straddle, hedge, constructive sale or other integrated transaction for tax purposes;

• a partnership, S corporation or other pass-through entity;

• an investor in a partnership, S corporation or other pass-through entity;

• a person that is required to report income with respect to ordinary shares or ADSs no later than such income is reported on an “applicable financial statement;”

• a person who received ordinary shares or ADSs in connection with the performance of services; and

• a person whose functional currency for U.S. federal income tax purposes is not the U.S. dollar.

If an entity treated as a partnership for U.S. federal income tax purposes holds ordinary shares or ADSs, the tax treatment of a partner will generally depend upon the status of the partner and upon the activities of the partnership. A partner of a partnership that owns or may acquire ordinary shares or ADSs should consult the partner’s tax advisor regarding the specific tax consequences of the acquisition and ownership of ordinary shares or ADSs.

YOU SHOULD CONSULT YOUR OWN ADVISOR REGARDING THE TAX CONSEQUENCES OF THE ACQUISITION, OWNERSHIP AND DISPOSITION OF ORDINARY SHARES AND ADSS IN LIGHT OF YOUR PARTICULAR CIRCUMSTANCES.

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U.S. holders

For purposes of this discussion, a “U.S. Holder” is any beneficial owner of an ordinary share or ADS that is, for U.S. federal income tax purposes:

• an individual who is a citizen or resident of the United States, any state thereof or the District of Columbia;

• a corporation created or organized under the laws of the United States, any state thereof or the District of Columbia;

• an estate the income of which is subject to U.S. federal income taxation regardless of its source; or,

• a trust (1) that validly elects to be treated as a U.S. person for U.S. federal income tax purposes, or (2) the administration over which a U.S. court can exercise primary supervision and all of the substantial decisions of which one or more U.S. persons have the authority to control.

Distributions

Subject to the discussion under “—Passive Foreign Investment Company,” below, the gross amount of distributions, if any, payable on ordinary shares and ADSs generally would be treated as dividend income to the extent paid out of current or accumulated earnings and profits (as determined for U.S. federal income tax purposes). A U.S. Holder would be required to include the amount of such distribution in gross income as a dividend (without reduction for any income tax withheld from such distribution). Because Amarin does not maintain calculations of its earnings and profits in accordance with U.S. federal income tax principles, U.S. Holders should assume that any distribution by Amarin with respect to the ordinary shares and ADSs will constitute ordinary dividend income.

Subject to the discussion under “—Passive Foreign Investment Company,” below, as long as our ordinary shares or ADSs (as applicable) are treated as publicly traded on an established securities market, or we are eligible for the benefits of the U.S.-Irish Tax Treaty, any distributions treated as dividends will generally be “qualified dividend income” in the hands of non-corporate U.S. Holders, provided that certain significant holding period and other requirements are met. Any dividends that are qualified dividend income will generally be taxed at preferential rates to a non-corporate U.S. Holder. Any dividends paid to a corporate holder will not be eligible for the dividends received deduction.

U.S. Holders generally may claim the amount of Irish withholding tax withheld either as a deduction from gross income or as a credit against U.S. federal income tax liability. However, the foreign tax credit is subject to numerous complex limitations that must be determined and applied on an individual basis. Generally, the credit cannot exceed the proportionate share of a U.S. Holder’s U.S. federal income tax liability that such U.S. Holder’s “foreign source” taxable income bears to such U.S. Holder’s worldwide taxable income. In applying this limitation, a U.S. Holder’s various items of income and deduction must be classified, under complex rules, as either “foreign source” or “U.S. source.” In addition, this limitation is calculated separately with respect to specific categories of income. The amount of a distribution with respect to the ordinary shares or ADSs that is treated as a “dividend” may be lower for U.S. federal income tax purposes than it is for Irish income tax purposes, potentially resulting in a reduced foreign tax credit for the U.S. Holder. Each U.S. Holder should consult its own tax advisors regarding the foreign tax credit rules.

The amount of a distribution paid to a U.S. Holder of ordinary shares or ADSs in foreign currency generally will be equal to the U.S. dollar value of such distribution based on the exchange rate applicable on the date of receipt. A U.S. Holder that does not convert foreign currency received as a distribution into U.S. dollars on the date of receipt generally will have a tax basis in such foreign currency equal to the U.S. dollar value of such

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foreign currency on the date of receipt. Such a U.S. Holder generally will recognize ordinary income or loss on the subsequent sale or other taxable disposition of such foreign currency (including an exchange for U.S. dollars).

Sale or other disposition of ordinary shares or ADSs

Subject to the discussion under “—Passive Foreign Investment Company,” below, in general, if you sell or otherwise dispose of ordinary shares or ADSs in a taxable disposition:

• you will recognize gain or loss equal to the difference (if any) between the U.S. dollar value of the amount realized on such sale or other taxable disposition and your adjusted tax basis in such ordinary shares or ADSs;

• any gain or loss will be capital gain or loss and will be long-term capital gain or loss if your holding period for the ordinary shares or ADSs sold or otherwise disposed of is more than one year at the time of such sale or other taxable disposition; and,

• any gain or loss will generally be treated as U.S.-source income for U.S. foreign tax credit purposes, although special rules apply to U.S. Holders who have a fixed place of business outside the United States to which this gain is attributable.

Under current law, long-term capital gains of non-corporate U.S. Holders are taxed at reduced rates. The deductibility of capital losses is subject to limitations.

In certain circumstances, amounts received by a U.S. Holder upon the redemption of ordinary shares or ADSs may be treated as a dividend with respect to such ordinary shares or ADSs, rather than as a payment in exchange for such ordinary shares or ADSs that results in the recognition of capital gain or loss. In these circumstances, the redemption payment would be included in a U.S. Holder’s gross income as a dividend to the extent such payment is made out of our earnings and profits (as described above). The determination of whether redemption of ordinary shares or ADSs will be treated as a dividend, rather than as a payment in exchange for such ordinary shares or ADSs, will depend, in part, on whether and to what extent the redemption reduces the U.S. Holder’s ownership in us (including as a result of certain constructive ownership attribution rules). The rules applicable to redemptions are complex, and each U.S. Holder should consult its own tax adviser to determine the consequences of any redemption.

Passive foreign investment company

PFIC Rules Generally.    U.S. Holders of ordinary shares and ADSs should be aware that each of Amarin and certain of its subsidiaries could constitute a “passive foreign investment company” (a “PFIC”) for U.S. federal income tax purposes. The tests for determining PFIC status for a taxable year depend upon the relative values of certain categories of assets and the relative amounts of certain kinds of income. The application of these factors depends upon our financial results for the year, which are beyond our ability to predict or control, and the application of the relevant rules is subject to legal and factual uncertainties. The Company reasonably believes that it was not classified as a PFIC in any of its last five completed fiscal years and does not reasonably expect to become a PFIC in 2019 or any future years. However, there can be no assurance in this regard.

In general terms, Amarin will be a PFIC for any tax year in which either (i) 75% or more of its gross income is passive income (the “income test”) or (ii) the average percentage, by fair market value, of its assets that produce or are held for the production of passive income is 50% or more (the “asset test”). “Passive income” includes, for example, dividends, interest, certain rents and royalties, certain gains from the sale of stock and securities, and certain gains from commodities transactions.

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If Amarin is a PFIC for any year, subject to the discussion of QEF and mark-to-market elections below, a U.S. taxpayer who disposes or is deemed to dispose of an ordinary share or ADS at a gain or who receives a distribution treated as an “excess distribution” on an ordinary share or ADS generally would be required to allocate such gain and distribution ratably to each day in the U.S. taxpayer’s holding period for the ordinary share or ADS in question.

The portion of any excess distributions including gains, which are treated for all purposes as excess distributions, allocated to the current tax year or to a year prior to the first year in which Amarin was a PFIC would be includible as ordinary income in the current tax year. In contrast, the portion of any excess distributions allocated to the first year in the U.S. Holder’s holding period in which Amarin was a PFIC and any subsequent year or years (excluding the current year) would be taxed at the highest marginal rate applicable to ordinary income for each year (regardless of the U.S. Holder’s actual marginal rate for that year and without reduction by any losses or loss carryforwards) and would be subject to interest charges to reflect the value of the U.S. federal income tax deferral.

In accordance with the rules above, if Amarin is or was a PFIC at any time during the U.S. Holder’s holding period, none of the gain recognized on the sale or other disposition of an ordinary share or ADS would be eligible for the preferential long-term capital gains rate. In addition, dividends generally will not be qualified dividend income if in the year of payment or the preceding year Amarin is a PFIC.

Certain elections may sometimes be used to reduce the adverse impact of the PFIC rules on U.S. Holders (“qualifying electing fund” (“QEF”) and “mark-to-market” elections), but these elections may accelerate the recognition of taxable income and may result in the recognition of ordinary income.

QEF Election.    The rules described above for excess distributions would not apply to a U.S. Holder if the U.S. Holder makes a timely QEF election for the first taxable year of the U.S. Holder’s holding period for ordinary shares or ADSs during which Amarin is a PFIC and Amarin complies with specified reporting requirements. A timely QEF election for a taxable year generally must be made on or before the due date (as may be extended) for filing the taxpayer’s U.S. federal income tax return for the year. A U.S. Holder who makes a QEF election generally must report and include in income on a current basis a pro rata share of Amarin’s ordinary earnings and net capital gain for any taxable year in which Amarin is a PFIC, whether or not those earnings or gains are distributed. A U.S. Holder who makes a QEF election must file a Form 8621 with its annual income tax return. For U.S. Holders who seek to make a QEF election, with respect to our ordinary shares or ADSs, Amarin will make available an information statement that will contain the necessary information required for making a QEF election and permit such U.S. Holders access to certain information in the event of an audit by the U.S. tax authorities.

If a U.S. Holder does not make a QEF election for the first taxable year of the U.S. Holder’s holding period for ordinary shares or ADSs during which Amarin is a PFIC, the QEF election will not be treated as timely and the adverse tax regime described above would apply to dispositions of or excess distributions on the ordinary shares or ADSs. In such case, a U.S. Holder may make a deemed sale election whereby the U.S. Holder would be treated as if the U.S. Holder had sold the ordinary shares or ADSs in a fully taxable sale at fair market value on the first day of such taxable year in which the QEF election takes effect. Such U.S. Holder would be required to recognize any gain on the deemed sale as an excess distribution and pay any tax and interest due on the excess distribution when making the deemed sale election. The effect of such further election would be to restart the U.S. Holder’s holding period in the ordinary shares or ADSs, subject to the QEF regime, and to purge the PFIC status of such ordinary shares or ADSs going forward.

Mark-to-Market Election.    If Amarin is or becomes a PFIC, a U.S. Holder of ordinary shares or ADSs may elect to recognize any gain or loss on ordinary shares or ADSs on a mark-to-market basis at the end of each taxable

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year, so long as the ordinary shares and ADSs, respectively, are regularly traded on a qualifying exchange. The mark-to-market election under the PFIC rules is an alternative to the QEF election. A U.S. Holder who makes a mark-to-market election generally must recognize as ordinary income all appreciation inherent in the U.S. Holder’s investment in ordinary shares or ADSs on a mark-to-market basis and may recognize losses inherent in such ordinary shares or ADSs only to the extent of prior mark-to-market gain recognition. The income and deductions entailed by the mark-to-market regime will increase and decrease the U.S. Holder’s adjusted basis in its ordinary shares or ADSs. Upon a sale or other disposition of ordinary shares or ADSs that have been marked-to-market, any gain recognized will be treated as ordinary income. The mark-to-market election must be made by the due date (as may be extended) for filing the U.S. Holder’s federal income tax return for the first year in which the election is to take effect. If a mark-to-market election is made after the first taxable year of a U.S. Holder’s holding period, any gain recognized in the year of the election will be treated like an excess distribution (as described above). Whether or not the mark-to-market election is available will depend on whether the ordinary shares or ADSs are regularly traded on a qualifying exchange and Amarin cannot provide assurance that the ordinary shares or ADSs will be considered “regularly traded” (which determination is based on the volume of trading of the ordinary shares or ADSs) for all years in which Amarin may be a PFIC.

Rules for Lower-Tier PFIC Subsidiaries.    Special adverse rules apply to U.S. Holders of ordinary shares or ADSs for any year in which Amarin is a PFIC and has a non-U.S. subsidiary that is also a PFIC (a “lower-tier PFIC”). If Amarin is or becomes a PFIC and a U.S. Holder does not make a QEF election (as described above) in respect of any lower-tier PFIC, the U.S. Holder could incur liability for the deferred tax and interest charge described above if (i) Amarin receives a distribution from, or disposes of all or part of its interest in, the lower-tier PFIC or (ii) the U.S. Holder disposes of all or part of its ordinary shares or ADSs. A QEF election that is made for ordinary shares or ADSs will not apply to a lower tier PFIC, although a separate QEF election may be made with respect to a lower-tier PFIC. For U.S. Holders who seek to make a QEF election, with respect to our ordinary shares or ADSs, Amarin will make available an information statement that will contain the necessary information required for making a QEF election with respect to any lower-tier PFIC and permit such U.S. Holders access to certain information in the event of an audit by the U.S. tax authorities. For U.S. Holders that make a mark-to-market election for Amarin, if available, no such election may be made with respect to the stock of a lower-tier PFIC that a U.S. Holder is treated as owning if such stock is not marketable. Hence, the mark-to-market election will not be effective to eliminate a U.S. Holder’s liability for the deferred tax and interest charge described above with respect to deemed dispositions of lower-tier PFIC stock or distributions from a lower-tier PFIC.

Taxpayer Reporting Obligations.    A U.S. Holder’s ownership of ordinary shares or ADSs in a PFIC generally must be reported by filing Form 8621 with the U.S. Holder’s annual U.S. federal income tax return. Every U.S. Holder who is a shareholder in a PFIC must file an annual report containing the information required by the Internal Revenue Service.

The PFIC rules are extremely complex, and U.S. Holders are urged to consult their own tax advisers regarding the potential tax consequences of Amarin being classified as a PFIC.

Medicare tax

Certain U.S. Holders that are individuals, estates or trusts are required to pay up to an additional 3.8% tax on the lesser of (i) the U.S. person’s “net investment income” (or “undistributed net investment income” in the case of an estate or trust) for the relevant taxable year and (ii) the excess of the U.S. person’s modified adjusted gross income (or adjusted gross income, in the case of an estate or trust) for the taxable year over a certain threshold (which in the case of individuals will be between $125,000 and $250,000, depending on the individual’s circumstances). A U.S. Holder’s net investment income will include dividends and capital gains on

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the U.S. Holder’s ordinary shares and ADSs. U.S. Holders should consult their own tax advisors regarding the effect, if any, of the Medicare tax on acquisition, ownership and disposition of ordinary shares or ADSs.

Taxpayer reporting obligations

Certain U.S. Holders that hold certain foreign financial assets are required to report information relating to such assets to the IRS, subject to certain exceptions. U.S. Holders may also be required to make other tax filings with respect to their investments in our ordinary shares and ADSs, including IRS Form 926 (Return by a U.S. Transferor of Property to a Foreign Corporation) Failure to provide such information could result in significant additional taxes and penalties.

U.S. Information reporting and backup withholding

U.S. Holders of ordinary shares and ADSs may be subject to information reporting and may be subject to backup withholding on distributions on ordinary shares and ADSs or on the proceeds from a sale or other disposition of ordinary shares and ADSs paid within the United States. Payments of distributions on, or the proceeds from the sale or other disposition of ordinary shares and ADSs to or through a foreign office of a broker generally will not be subject to backup withholding, although information reporting may apply to those payments in certain circumstances. Backup withholding will generally not apply, however, to a U.S. Holder who:

• furnishes a correct taxpayer identification number and certifies that the U.S. Holder is not subject to backup withholding on IRS Form W-9, Request for Taxpayer Identification Number and Certification (or substitute form); or

• is otherwise exempt from backup withholding.

Backup withholding is not an additional tax. Any amounts withheld from a payment to a holder under the backup withholding rules may be credited against the holder’s U.S. federal income tax liability, and a holder may obtain a refund of any excess amounts withheld by filing the appropriate claim for refund with the IRS in a timely manner.

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Underwriting

We are offering ADSs described in this prospectus supplement through a number of underwriters. J.P. Morgan Securities LLC, Goldman Sachs & Co. LLC, Jefferies LLC and Cantor Fitzgerald & Co. are acting as the joint book-running managers and representatives of the underwriters. We have entered into an underwriting agreement with the underwriters. Subject to the terms and conditions of the underwriting agreement, we have agreed to sell to the underwriters, and each underwriter has severally agreed to purchase, at the public offering price less the underwriting discounts and commissions set forth on the cover page of this prospectus supplement, the number of ADSs listed next to its name in the following table:

Name	Number of ADSs
J.P. Morgan Securities LLC		8,222,223
Goldman Sachs & Co. LLC		6,888,890
Jefferies LLC		3,333,333
Cantor Fitzgerald & Co.		3,333,333
H.C. Wainwright & Co., LLC		222,222
Roth Capital Partners, LLC		222,222
Total		22,222,223

The underwriters are committed to purchase all the ADSs offered by us if they purchase any ADSs. The underwriting agreement also provides that if an underwriter defaults, the purchase commitments of non-defaulting underwriters may also be increased or the offering may be terminated.

The underwriters propose to offer the ADSs directly to the public at the public offering price set forth on the cover page of this prospectus supplement and to certain dealers at that price less a concession not in excess of $0.459 per share. After the offering of the ADSs to the public, the offering price and other selling terms may be changed by the underwriters. Sales of ADSs made outside of the United States may be made by affiliates of the underwriters.

The underwriters have an option to buy up to 3,333,333 additional ADSs from us. The underwriters have 30 days from the date of this prospectus supplement to exercise this option to purchase additional ADSs. If any ADSs are purchased with this option to purchase additional ADSs, the underwriters will purchase ADSs in approximately the same proportion as shown in the table above. If any additional ADSs are purchased, the underwriters will offer the additional ADSs on the same terms as those on which the ADSs are being offered.

The underwriting fee is equal to the public offering price per ADSs less the amount paid by the underwriters to us per ADSs. The underwriting fee is $0.765 per ADSs. The following table shows the per ADSs and total underwriting discounts and commissions to be paid to the underwriters assuming both no exercise and full exercise of the underwriters’ option to purchase additional ADSs.

	Without exercise of option to purchase additional ADSs		With full exercise of option to purchase additional ADSs
Per Share	$	0.765	$	0.765
Total	$	17,000,001	$	19,550,000

We estimate that the total expenses of this offering, including registration, filing and listing fees, printing fees and legal and accounting expenses, but excluding the underwriting discounts and commissions, will be approximately $1,000,000. We have agreed to reimburse the underwriters for certain expenses related to qualification of our ADSs under states securities laws and the clearing of this offering with the Financial

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Industry Regulatory Authority. In addition, the underwriters have agreed to reimburse us for certain of our expenses in connection with this offering.

A prospectus supplement in electronic format may be made available on the web sites maintained by one or more underwriters, or selling group members, if any, participating in the offering. The underwriters may agree to allocate a number of ADSs to underwriters and selling group members for sale to their online brokerage account holders. Internet distributions will be allocated by the representative to underwriters and selling group members that may make Internet distributions on the same basis as other allocations.

We, our executive officers and directors have agreed, subject to specified exceptions, not to directly or indirectly:

• sell, offer, contract or grant any option to sell (including, without limitation, any short sale), pledge, transfer, establish an open “put equivalent position” within the meaning of Rule 16a-1(h) under the Exchange Act, or otherwise dispose of any ADSs or ordinary shares, options or warrants to acquire ADSs or ordinary shares or securities exchangeable or exercisable for or convertible into ADSs or ordinary shares;

• enter into any swap or other agreement that transfers, in whole or in part, any of the economic consequences of ownership of the ADSs, ordinary shares or such other securities; or

• publicly announce the intention to do any of the foregoing.

The restrictions described above do not apply to:

• transfers by gift, will or intestate succession to the immediate family of a holder or to a family limited partnership, trust or other financial vehicle, the partners, owners or beneficiaries of which, as the case may be, are exclusively the holder and/or a member or members of the holder’s immediate family;

• the distribution or transfer of any ADSs or ordinary shares owned by the holder to limited partners, members or stockholders of the holder;

• the sale or transfer of ADSs or ordinary shares pursuant to any written trading plan or agreement with a broker designed to comply with Rule 10b5-1(c)(1) of the Exchange Act (a “Rule 10b5-1 Plan”) (which Rule 10b5-1 Plan may not be amended during the lock-up period);

• entering into any new Rule 10b5-1 Plan during the lock-up period, provided that any such Rule 10b5-1 Plan shall specify that no sales of securities subject to the lock-up agreement may be sold during the lock-up period;

• any sales or other dispositions of ADSs or ordinary shares acquired in open market transactions after the consummation of this offering;

• the grant of options, rights or warrants by us pursuant to any of our existing employee stock option, stock bonus, benefit or other employee compensation plans or arrangements or the issuance of ordinary shares or ADSs (A) pursuant to any exercise of options, rights or warrants granted under such plans or arrangements or (B) pursuant to any exercise of rights or warrants or the conversion or exchange of any existing securities convertible into or exchangeable for ordinary shares or ADSs; or

• ordinary shares or ADSs issued and sold by us to a third party as part of a research or development license, joint venture, promotion, marketing or commercialization agreement or other similar collaboration or partnership between us and such third party relating to one or more of our product candidates, products or technologies; provided, that (A) the amount of shares received by such third party is less than 20% of the outstanding ordinary shares and ADSs and (B) such third party agrees to be bound by the terms of the lock-up agreement with respect to such shares.

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The above restrictions terminate (i) for us, on the 90th day after the date of this prospectus supplement, and (ii) for our executive officers and directors, the later of (i) the close of trading on the date that is 30 days after the date of this prospectus supplement and (ii) the close of trading on the date that is two trading days after the date of the Company’s public announcement of the review conclusion of the FDA regarding the Company’s sNDA submitted to the FDA on March 28, 2019, including for clarity approval by the FDA of such sNDA or a complete response letter.

J.P. Morgan Securities LLC may, in its sole discretion, at any time or from time to time before the termination of the restricted period, release all or any portion of the securities subject to lock-up agreements. There are no existing agreements between the underwriter and any of our shareholders who will execute a lock-up agreement, providing consent to the sale of ADSs prior to the expiration of the lock-up period.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act.

Our ADSs are listed on the Nasdaq Global Market under the symbol “AMRN”.

In connection with this offering, the underwriters may engage in stabilizing transactions, which involves making bids for, purchasing and selling ADSs in the open market for the purpose of preventing or retarding a decline in the market price of ADSs while this offering is in progress. These stabilizing transactions may include making short sales of ADSs, which involves the sale by the underwriters of a greater number of ADSs than they are required to purchase in this offering, and purchasing ADSs on the open market to cover positions created by short sales. Short sales may be “covered” shorts, which are short positions in an amount not greater than the underwriters’ option to purchase additional ADSs referred to above, or may be “naked” shorts, which are short positions in excess of that amount. The underwriters may close out any covered short position either by exercising their option to purchase additional ADSs, in whole or in part, or by purchasing ADSs in the open market. In making this determination, the underwriters will consider, among other things, the price of ADSs available for purchase in the open market compared to the price at which the underwriters may purchase ADSs through the option to purchase additional ADSs. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of the ADSs in the open market that could adversely affect investors who purchase in this offering. To the extent that the underwriters create a naked short position, they will purchase ADSs in the open market to cover the position.

The underwriters have advised us that, pursuant to Regulation M of the Securities Act, they may also engage in other activities that stabilize, maintain or otherwise affect the price of the ADSs, including the imposition of penalty bids. This means that if the representative of the underwriters purchase ADSs in the open market in stabilizing transactions or to cover short sales, the representative can require the underwriters that sold those ADSs as part of this offering to repay the underwriting discount received by them.

These activities may have the effect of raising or maintaining the market price of the ADSs or preventing or retarding a decline in the market price of the ADSs, and, as a result, the price of the ADSs may be higher than the price that otherwise might exist in the open market. If the underwriters commence these activities, they may discontinue them at any time. The underwriters may carry out these transactions on the Nasdaq Global Select Market, in the over-the-counter market or otherwise.

In addition, in connection with this offering certain of the underwriters (and selling group members) may engage in passive market making transactions in our ADSs on the Nasdaq Stock Market prior to the pricing and completion of this offering. Passive market making consists of displaying bids on the Nasdaq Stock Market no higher than the bid prices of independent market makers and making purchases at prices no higher than these independent bids and effected in response to order flow. Net purchases by a passive market maker on each day are generally limited to a specified percentage of the passive market maker’s average daily trading volume in

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the ADSs during a specified period and must be discontinued when such limit is reached. Passive market making may cause the price of our ADSs to be higher than the price that otherwise would exist in the open market in the absence of these transactions. If passive market making is commenced, it may be discontinued at any time.

Other than in the United States, no action has been taken by us or the underwriters that would permit a public offering of the securities offered by this prospectus supplement in any jurisdiction where action for that purpose is required. The securities offered by this prospectus supplement may not be offered or sold, directly or indirectly, nor may this prospectus supplement or any other offering material or advertisements in connection with the offer and sale of any such securities be distributed or published in any jurisdiction, except under circumstances that will result in compliance with the applicable rules and regulations of that jurisdiction. Persons into whose possession this prospectus supplement comes are advised to inform themselves about and to observe any restrictions relating to the offering and the distribution of this prospectus supplement. This prospectus supplement does not constitute an offer to sell or a solicitation of an offer to buy any securities offered by this prospectus supplement in any jurisdiction in which such an offer or a solicitation is unlawful.

Certain of the underwriters and their affiliates have provided in the past to us and our affiliates and may provide from time to time in the future certain commercial banking, financial advisory, investment banking and other services for us and such affiliates in the ordinary course of their business, for which they have received and may continue to receive customary fees and commissions. In addition, from time to time, certain of the underwriters and their affiliates may effect transactions for their own account or the account of customers, and hold on behalf of themselves or their customers, long or short positions in our debt or equity securities or loans, and may do so in the future. The underwriters and certain of their affiliates may also communicate independent investment recommendations, market color or trading ideas and/or publish or express independent research views in respect of such securities or instruments and may at any time hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

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Notice to prospective investors

European Economic Area

In relation to each member state of the European Economic Area which has implemented the Prospectus Directive, each referred to herein as a Relevant Member State, with effect from and including the date on which the Prospectus Directive is implemented in that Relevant Member State, no offer of securities may be made to the public in that Relevant Member State other than:

• to any legal entity which is a “qualified investor” as defined in the Prospectus Directive;

• to fewer than 150 natural or legal persons (other than qualified investors as defined in the Prospectus Directive), as permitted under the Prospectus Directive, subject to obtaining the prior consent of the representative of the underwriters for any such offer; or

• in any other circumstances falling within Article 3(2) of the Prospectus Directive,

provided that no such offer of securities shall require the Company or any of the underwriters to publish a prospectus pursuant to Article 3 of the Prospectus Directive or supplement a prospectus pursuant to Article 16 of the Prospectus Directive.

Each person in a Relevant Member State who initially acquires any securities or to whom any offer is made will be deemed to have represented, acknowledged and agreed that it is a “qualified investor” within the meaning of the law in that Relevant Member State implementing Article 2(1)(e) of the Prospectus Directive. In the case of any securities being offered to a financial intermediary as that term is used in Article 3(2) of the Prospectus Directive, each such financial intermediary will be deemed to have represented, acknowledged and agreed that the securities acquired by it in the offer have not been acquired on a non-discretionary basis on behalf of, nor have they been acquired with a view to their offer or resale to, persons in circumstances which may give rise to an offer of any securities to the public other than their offer or resale in a Relevant Member State to qualified investors as so defined or in circumstances in which the prior consent of the representative has been obtained to each such proposed offer or resale.

We, the representative and its affiliates will rely upon the truth and accuracy of the foregoing representations, acknowledgements and agreements.

This prospectus has been prepared on the basis that any offer of securities in any Relevant Member State will be made pursuant to an exemption under the Prospectus Directive from the requirement to publish a prospectus for offers of securities. Accordingly any person making or intending to make an offer in that Relevant Member State of securities which are the subject of the offering contemplated in this prospectus may only do so in circumstances in which no obligation arises for us or any of the underwriters to publish a prospectus pursuant to Article 3 of the Prospectus Directive in relation to such offer. Neither we nor the underwriters have authorized, nor do we or they authorize, the making of any offer of securities in circumstances in which an obligation arises for us or the underwriters to publish a prospectus for such offer.

For the purposes of this provision, the expression an “offer to the public” in relation to any securities in any Relevant Member State means the communication in any form and by any means of sufficient information on the terms of the offer and the securities to be offered so as to enable an investor to decide to purchase or subscribe the securities, as the same may be varied in that Relevant Member State by any measure implementing the Prospectus Directive in that Relevant Member State and the expression “Prospectus Directive” means Directive 2003/71/EC (and amendments thereto, including the 2010 PD Amending Directive), and includes any relevant implementing measure in the Relevant Member State and the expression “2010 PD Amending Directive” means Directive 2010/73/EU.

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United Kingdom

In addition, in the United Kingdom, this prospectus supplement is being distributed only to, and is directed only at, and any offer subsequently made may only be directed at persons who are “qualified investors” (as defined in the Prospectus Directive) (i) who have professional experience in matters relating to investments falling within Article 19 (5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended (the “Order”) and/or (ii) who are high net worth companies (or persons to whom it may otherwise be lawfully communicated) falling within Article 49(2)(a) to (d) of the Order (all such persons together being referred to as “relevant persons”).

Any person in the United Kingdom that is not a relevant person should not act or rely on the information included in this prospectus supplement or use it as basis for taking any action. In the United Kingdom, any investment or investment activity that this prospectus supplement relates to may be made or taken exclusively by relevant persons. Any person in the United Kingdom that is not a relevant person should not act or rely on this prospectus supplement or any of its contents.

Canada

ADSs may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of ADSs must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

Australia

This prospectus supplement and the accompanying prospectus are not disclosure documents for the purposes of Australia’s Corporations Act 2001 (Cth) of Australia, or Corporations Act, have not been lodged with the Australian Securities & Investments Commission and are only directed to the categories of exempt persons set out below. Accordingly, if you receive this prospectus supplement and the accompanying prospectus in Australia:

You confirm and warrant that you are either:

• a “sophisticated investor” under section 708(8)(a) or (b) of the Corporations Act;

• a “sophisticated investor” under section 708(8)(c) or (d) of the Corporations Act and that you have provided an accountant’s certificate to the company which complies with the requirements of section 708(8)(c)(i) or (ii) of the Corporations Act and related regulations before the offer has been made; or

• a “professional investor” within the meaning of section 708(11)(a) or (b) of the Corporations Act.

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To the extent that you are unable to confirm or warrant that you are an exempt sophisticated investor or professional investor under the Corporations Act any offer made to you under this prospectus supplement and the accompanying prospectus is void and incapable of acceptance.

You warrant and agree that you will not offer any of the ADSs issued to you pursuant to this prospectus supplement and the accompanying prospectus for resale in Australia within 12 months of those securities being issued unless any such resale offer is exempt from the requirement to issue a disclosure document under section 708 of the Corporations Act.

Hong Kong

No securities have been offered or sold, and no securities may be offered or sold, in Hong Kong, by means of any document, other than to persons whose ordinary business is to buy or sell shares or debentures, whether as principal or agent; or to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571) of Hong Kong and any rules made under that Ordinance; or in other circumstances which do not result in the document being a “prospectus” as defined in the Companies Ordinance (Cap. 32) of Hong Kong or which do not constitute an offer to the public within the meaning of the Companies Ordinance (Cap.32) of Hong Kong. No document, invitation or advertisement relating to the securities has been issued or may be issued or may be in the possession of any person for the purpose of issue (in each case whether in Hong Kong or elsewhere), which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted under the securities laws of Hong Kong) other than with respect to securities which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571) of Hong Kong and any rules made under that Ordinance.

This prospectus supplement and the accompanying prospectus have not been registered with the Registrar of Companies in Hong Kong. Accordingly, this prospectus supplement and the accompanying prospectus may not be issued, circulated or distributed in Hong Kong, and the securities may not be offered for subscription to members of the public in Hong Kong. Each person acquiring the securities will be required, and is deemed by the acquisition of the securities, to confirm that he is aware of the restriction on offers of the securities described in this prospectus supplement and the accompanying prospectus and the relevant offering documents and that he is not acquiring, and has not been offered any securities in circumstances that contravene any such restrictions.

Japan

The offering has not been and will not be registered under the Financial Instruments and Exchange Law of Japan (Law No. 25 of 1948 of Japan, as amended), or FIEL, and the underwriter will not offer or sell any securities, directly or indirectly, in Japan or to, or for the benefit of, any resident of Japan (which term as used herein means, unless otherwise provided herein, any person resident in Japan, including any corporation or other entity organized under the laws of Japan), or to others for re-offering or resale, directly or indirectly, in Japan or to a resident of Japan, except pursuant to an exemption from the registration requirements of, and otherwise in compliance with, the FIEL and any other applicable laws, regulations and ministerial guidelines of Japan.

Singapore

This prospectus supplement and the accompanying prospectus have not been and will not be lodged or registered with the Monetary Authority of Singapore. Accordingly, this prospectus supplement and the accompanying prospectus and any other document or material in connection with the offer or sale, or the

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invitation for subscription or purchase of the securities may not be issued, circulated or distributed, nor may the securities be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to the public or any member of the public in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore, or the SFA, (ii) to a relevant person as defined under Section 275(2), or any person pursuant to Section 275(1A) of the SFA, and in accordance with the conditions, specified in Section 275 of the SFA, or (iii) otherwise pursuant to, and in accordance with the conditions of any other applicable provision of the SFA.

Where the securities are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

• a corporation (which is not an accredited investor as defined under Section 4A of the SFA) the sole business of which is to hold investments and the entire share capital of which is owned by one or more individuals, each of whom is an accredited investor; or

• a trust (where the trustee is not an accredited investor) whose sole purpose is to hold investments and each beneficiary is an accredited investor,

shares, debentures and units of shares and debentures of that corporation or the beneficiaries’ rights and interest in that trust shall not be transferable for six months after that corporation or that trust has acquired the Offer Shares under Section 275 of the SFA except:

• to an institutional investor under Section 274 of the SFA or to a relevant person defined in Section 275(2) of the SFA, or to any person pursuant to an offer that is made on terms that such shares, debentures and units of shares and debentures of that corporation or such rights and interest in that trust are acquired at a consideration of not less than $200,000 (or its equivalent in a foreign currency) for each transaction, whether such amount is to be paid for in cash or by exchange of securities or other assets, and further for corporations, in accordance with the conditions, specified in Section 275 of the SFA;

• where no consideration is given for the transfer; or

• where the transfer is by operation of law.

Switzerland

The securities may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange, or SIX, or on any other stock exchange or regulated trading facility in Switzerland. This prospectus supplement and the accompanying prospectus have been prepared without regard to the disclosure standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Neither this prospectus supplement and the accompanying prospectus nor any other offering or marketing material relating to the securities or the offering may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this prospectus supplement and the accompanying prospectus nor any other offering or marketing material relating to the offering, the Company or the securities have been or will be filed with or approved by any Swiss regulatory authority. In particular, this prospectus supplement and the accompanying prospectus will not be filed with, and the offer of securities will not be supervised by, the Swiss Financial Market Supervisory Authority FINMA, or FINMA, and the offer of securities has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes, or CISA. The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of securities.

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Israel

These documents do not constitute a prospectus supplement or prospectus under the Israeli Securities Law, 5728-1968, or the Securities Law, and has not been filed with or approved by the Israel Securities Authority. In the State of Israel, this document is being distributed only to, and is directed only at, and any offer of the ADSs is directed only at, investors listed in the first addendum, or the Addendum, to the Israeli Securities Law, consisting primarily of joint investment in trust funds, provident funds, insurance companies, banks, portfolio managers, investment advisors, members of the Tel Aviv Stock Exchange, underwriters, venture capital funds, entities with equity in excess of NIS 50 million and “qualified individuals”, each as defined in the Addendum (as it may be amended from time to time), collectively referred to as qualified investors (in each case purchasing for their own account or, where permitted under the Addendum, for the accounts of their clients who are investors listed in the Addendum). Qualified investors will be required to submit written confirmation that they fall within the scope of the Addendum, are aware of the meaning of same and agree to it.

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Legal matters

Goodwin Procter LLP of Boston, Massachusetts is acting as counsel to the Company in connection with this offering. K&L Gates LLP of London, England, is acting as special counsel to the Company in connection with this offering and will issue an opinion with respect to the validity of the issuance of the securities being offered hereby. Cahill Gordon & Reindel LLP of New York, New York is counsel to the underwriters in connection with this offering.

Experts

The consolidated financial statements of Amarin Corporation plc appearing in Amarin Corporation plc’s Annual Report (Form 10-K) for the year ended December 31, 2018, and the effectiveness of Amarin Corporation plc’s internal control over financial reporting as of December 31, 2018 have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

Where you can find more information

This prospectus supplement and the accompanying prospectus are part of the registration statement on Form S-3 we filed with the SEC under the Securities Act and do not contain all the information set forth in the registration statement. Whenever a reference is made in this prospectus supplement or the accompanying prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference in this prospectus supplement and the accompanying prospectus for a copy of such contract, agreement or other document. For additional information about our company, please refer to other documents we have filed with the SEC and that are incorporated by reference into this prospectus supplement and the accompanying prospectus, as listed under the heading “Incorporation of Certain Information by Reference” in this prospectus supplement and the accompanying prospectus. Additional information about us can be found on our website, at www.amarincorp.com, and in our filings with the SEC. Copies of our filings with the SEC are available online at www.sec.gov and our website at www.amarincorp.com. We have included the SEC’s website address and our website address as inactive textual references only. Neither the contents of the SEC’s website or our website, nor any other website that may be accessed from such websites, is incorporated in or otherwise considered a part of this prospectus supplement or the accompanying prospectus except as expressly set forth under the heading “Incorporation of Certain Information by Reference” in this prospectus supplement and the accompanying prospectus.

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Incorporation of certain information by reference

The SEC allows us to incorporate by reference information from other documents that we file with it, which means that we can disclose important information to you by referring you to another document that we have filed separately with the SEC. You should read the information incorporated by reference because it is an important part of this prospectus supplement and the accompanying prospectus. Information in this prospectus supplement supersedes information incorporated by reference that we filed with the SEC prior to the date of this prospectus supplement, while information that we file later with the SEC will automatically update and supersede the information in this prospectus supplement and the accompanying prospectus. We incorporate by reference into this prospectus supplement and the accompanying prospectus the information or documents listed below that we have filed with the SEC:

1. Our Annual Report on Form 10-K for the year ended December 31, 2018, filed with the SEC on February 27, 2019;

2. The information specifically incorporated by reference into our 2018 Annual Report on Form 10-K referred to above from our definitive proxy statement on Schedule 14A, filed with the SEC on April 25, 2019;

3. Our Quarterly Report on Form 10-Q for the period ended March 31, 2019 (filed with the SEC on May 1, 2019);

4. Our Current Reports on Form 8-K (other than information furnished rather than filed) filed with the SEC on February 8, 2019, April 1, 2019, May  23, 2019, May 29, 2019 and July 17, 2019; and

5. The section entitled “Description of Registrant’s Securities to be Registered” contained in the Registrant’s Registration Statement on Form 8-A filed with the SEC on March 19, 1993, including any amendment or report filed for the purpose of updating such description.

All reports and other documents we subsequently file pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act prior to the termination of this offering, but excluding any information furnished to, rather than filed with, the SEC, will also be incorporated by reference into this prospectus supplement and deemed to be part of this prospectus supplement from the date of the filing of such reports and documents.

Any statement contained in any document incorporated by reference herein shall be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained in this prospectus supplement modifies or supersedes such statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus supplement.

We will furnish without charge to you, upon written or oral request, a copy of any or all of the documents incorporated by reference, including exhibits to these documents. You should direct any requests for documents to: Amarin Corporation plc, c/o Amarin Pharma, Inc., 1430 Route 206, Bedminster, NJ 07921, attention: Investor Relations, or by telephone request to (908) 719-1315.

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Prospectus

Ordinary shares

Ordinary shares, in the form of American Depositary Shares

Preference shares

Preference shares, in the form of American Depositary Shares

Debt securities

Warrants

We or our selling security holders may offer and sell from time to time up to an indeterminate number of our: ordinary shares, each of which may be represented by one American Depositary Share; preference shares, each of which may be represented by one American Depositary Share; senior or subordinated debt securities; warrants to purchase any securities that may be sold under this prospectus; and any combination of these securities, individually or as units. We will describe in a prospectus supplement the securities we are offering and selling, as well as the specific terms of the securities. We will not receive any proceeds from the sale of securities by our selling security holders.

We or our selling security holders may offer these securities in amounts, at prices and on terms determined at the time of offering. We or our selling security holders may sell the securities directly to you, through agents, or through underwriters and dealers. If we or our selling security holders use agents, underwriters or dealers to sell the securities, we will name them and describe their compensation in a prospectus supplement. You should read this prospectus and the accompanying prospectus supplement carefully before you invest.

Our American Depositary Shares representing ordinary shares are traded on the NASDAQ Capital Market under the symbol “AMRN”. A separate Registration Statement on Form F-6 for the registration of American Depositary Shares issuable upon deposit of the ordinary shares was previously filed with the Securities and Exchange Commission and was effective on August 12, 2016 (Reg. File No. 333-213106). If we decide to list any of these other securities on a national securities exchange upon issuance, the applicable prospectus supplement to this prospectus will identify the exchange and the date when we expect trading to begin. On February 28, 2017, the closing price of our American Depositary Shares on the NASDAQ Capital Market was $3.40 per share.

Investing in our securities involves certain risks. See “Risk Factors” beginning on page 4 of this prospectus and in the applicable prospectus supplement for certain risks you should consider. You should read the entire prospectus carefully before you make your investment decision.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is March 1, 2017.

Table of Contents

	Page
Prospectus summary		1
Risk factors		4
Special note regarding forward-looking statements		4
Description of securities		6
Certain material U.K. tax considerations		34
Certain material Irish tax considerations		36
Use of proceeds		38
Ratio of earnings to fixed charges		39
Selling security holders		39
Plan of distribution		40
Legal matters		43
Experts		43
Incorporation of certain information by reference		44
Where you can find more information		45

Prospectus summary

This summary only highlights the more detailed information appearing elsewhere in this prospectus or incorporated by reference in this prospectus. It may not contain all of the information that is important to you. You should carefully read the entire prospectus and the documents incorporated by reference in this prospectus before deciding whether to invest in our securities.

Unless otherwise indicated or the context requires otherwise, in this prospectus and any prospectus supplement hereto, references to “Amarin,” “our company,” “we,” “us” and “our” mean Amarin Corporation plc, a public limited company incorporated under the laws of England and Wales.

About this prospectus

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or SEC, utilizing a shelf registration process. Under the shelf registration process, we or our selling security holders may offer the securities described in this prospectus from time to time at prices and on terms to be determined by market conditions at the time of offering. This prospectus provides you with a general description of the securities we or our selling security holders may offer. Each time we or our selling security holders offer a type or series of securities, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities, including, to the extent applicable:

• designation or classification;

• aggregate principal amount or aggregate offering price;

• maturity;

• original issue discount, if any;

• rates and times of payment of interest, dividends or other payments, if any;

• redemption, conversion, exchange, settlement or sinking fund terms, if any;

• conversion, exchange or settlement prices or rates, if any, and, if applicable, any provisions for changes to or adjustments in the conversion, exchange or settlement prices or rates and in the securities or other property receivable upon conversion, exchange or settlement;

• ranking;

• restrictive covenants, if any;

• voting or other rights, if any; and

• important U.S. federal income tax considerations not otherwise described herein.

Registration of the securities covered by this prospectus does not mean that these securities will necessarily be offered or sold. As of the date of filing this registration statement, we have no specific plans for selling the securities registered hereunder.

A prospectus supplement may include a discussion of risks or other special considerations applicable to us or the offered securities. A prospectus supplement may also add, update or change information in this prospectus. If there is any inconsistency between the information in this prospectus and the applicable prospectus

1

supplement, you must rely on the information in the prospectus supplement. Please carefully read both this prospectus, including the information incorporated by reference into this prospectus, and the applicable prospectus supplement together with additional information described under the heading “Where You Can Find More Information.” This prospectus may not be used to offer or sell any securities unless accompanied by a prospectus supplement.

The registration statement containing this prospectus, including exhibits to the registration statement, provides additional information about us and the securities offered under this prospectus. The registration statement can be read at the SEC website or at the SEC’s public reading room mentioned under the heading “Where You Can Find More Information.”

We have not authorized any broker-dealer, salesperson or other person to give any information or to make any representation other than those contained or incorporated by reference in this prospectus and the accompanying supplement to this prospectus. You must not rely upon any information or representation not contained or incorporated by reference in this prospectus or the accompanying prospectus supplement. This prospectus and the accompanying supplement to this prospectus do not constitute an offer to sell or the solicitation of an offer to buy securities, nor do this prospectus and the accompanying supplement to this prospectus constitute an offer to sell or the solicitation of an offer to buy securities in any jurisdiction to any person to whom it is unlawful to make such offer or solicitation. The information contained in this prospectus and the accompanying prospectus supplement speaks only as of their respective dates and may not reflect subsequent changes in our business, financial condition, results of operations and prospects even though this prospectus and any accompanying prospectus supplement is delivered or securities are sold on a later date.

We or our selling security holders may sell the securities directly to or through underwriters, dealers or agents. We or our selling security holders, and our underwriters or agents, reserve the right to accept or reject all or part of any proposed purchase of securities. If we or our selling security holders do offer securities through underwriters or agents, we will include in the applicable prospectus supplement:

• the names of those underwriters or agents;

• applicable fees, discounts and commissions to be paid to them;

• details regarding over-allotment options, if any; and

• the net proceeds to us or our selling security holders.

About Amarin Corporation plc

We are a biopharmaceutical company with expertise in lipid science focused on the commercialization and development of therapeutics to improve cardiovascular health.

Our lead product, Vascepa® (icosapent ethyl) capsules, is approved by the U.S. Food and Drug Administration, or FDA, for use as an adjunct to diet to reduce triglyceride levels in adult patients with severe (TG ³500mg/dL) hypertriglyceridemia. In August 2015, based on a federal court decision, we also began marketing Vascepa in the United States for the treatment of patients with high triglyceride levels (TG ³200mg/dL and <500mg/dL) who are also on statin therapy for elevated low-density lipoprotein cholesterol. Vascepa is available in the United States by prescription only. We began selling and marketing Vascepa in the United States in January 2013. We sell Vascepa principally to a limited number of major wholesalers, as well as selected regional wholesalers and specialty pharmacy providers, or collectively, its Distributors, that in turn resell Vascepa to

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retail pharmacies for subsequent resale to patients and health care providers. We market Vascepa through our sales force of approximately 150 sales professionals, including sales representatives and their managers. In addition, in March 2014, we entered into a co-promotion agreement with Kowa Pharmaceuticals America, Inc. under which approximately 250 Kowa Pharmaceuticals America, Inc. sales representatives began to devote a substantial portion of their time to promoting Vascepa starting in May 2014. In February 2015, we entered into an agreement with Eddingpharm (Asia) Macao Commercial Offshore Limited related to the development and commercialization of Vascepa in Mainland China, Hong Kong, Macau and Taiwan. We are currently focused on completing the ongoing REDUCE-IT (Reduction of Cardiovascular Events with EPA—Intervention Trial) cardiovascular outcomes study of Vascepa, which we started in December 2011. REDUCE-IT, a multinational, prospective, randomized, double-blind, placebo-controlled study, is the first prospective cardiovascular outcomes study of any drug in a population of patients who, despite stable statin therapy, have elevated triglyceride levels. Based on the results of REDUCE-IT, we plan to seek additional indicated uses for Vascepa. In REDUCE-IT, cardiovascular event rates for patients on stable statin therapy plus 4 grams per day of Vascepa will be compared to cardiovascular event rates for patients on stable statin therapy plus placebo. In 2016, we completed patient enrollment and randomization of 8,175 individual patients into the REDUCE-IT study, exceeding the 8,000 patients targeted for the trial. We operate in one business segment. American Depositary Shares representing our ordinary shares are listed on the NASDAQ Capital Market under the symbol “AMRN.”

Corporate information

Amarin Corporation plc (formerly Ethical Holdings plc) is a public limited company listed in the United States on the NASDAQ Capital Market. Amarin was originally incorporated in England as a private limited company on March 1, 1989 under the Companies Act 1985, and re-registered in England as a public limited company on March 19, 1993.

Our registered office is located at One New Change, London EC4M 9AF, England. Our principal executive offices are located at 2 Pembroke House, Upper Pembroke Street 28-32, Dublin 2, Ireland. Our primary office in the United States is located at 1430 Route 206, Bedminster, New Jersey 07921. Our telephone number at that location is (908) 719-1315. Our website address is www.amarincorp.com. Information contained on, or accessible through, our website is not a part of this prospectus.

For additional information about our company, please refer to other documents we have filed with the SEC and that are incorporated by reference into this prospectus, as listed under the heading “Incorporation of Certain Information by Reference.” Additional information about us can be found in our periodic and current reports filed with the SEC. Copies of our current and periodic reports filed with the SEC are available at the SEC Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549, and online at www.sec.gov.

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Risk factors

Before making an investment decision, you should carefully consider the risks described under “Risk Factors” in the applicable prospectus supplement, together with all of the other information appearing in this prospectus or incorporated by reference into this prospectus and any applicable prospectus supplement, in light of your particular investment objectives and financial circumstances. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. The trading price of our securities could decline due to any of these risks, and you may lose all or part of your investment. This prospectus and the incorporated documents also contain forward-looking statements that involve risks and uncertainties. Our actual results could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks mentioned elsewhere in this prospectus.

Special note regarding forward-looking statements

This prospectus and the documents incorporated by reference into it contain forward-looking statements. Forward-looking statements relate to future events or our future financial performance. We generally identify forward-looking statements by terminology such as “may,” “would,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “contemplates,” “believes,” “estimates,” “predicts,” “assume,” “intend,” “potential,” “continue” or other similar words or the negative of these terms. These statements are only predictions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our business, financial condition and results of operations. The outcome of the events described in these forward-looking statements is subject to risks, uncertainties and other factors referenced under in “Risk Factors” in this prospectus and described in any prospectus supplement and our periodic filings with the SEC incorporated by reference in this prospectus or any prospectus supplement. Accordingly, you should not place undue reliance upon these forward-looking statements. We cannot assure you that the events and circumstances reflected in the forward-looking statements will be achieved or occur, the timing of events and circumstances and actual results could differ materially from those projected in the forward looking statements. Forward-looking statements contained in this prospectus include, but are not limited to, statements about:

• our ability to generate revenue and otherwise maintain sufficient cash and other liquid resources to meet our operating and any debt service requirements;

• the success of our current and future research and development activities and clinical trials, including the timing and nature of any interim or final results of such trials;

• decisions by regulatory authorities regarding whether and when to approve our drug applications, as well as their decisions regarding labeling and other matters that could affect the commercial potential of our products;

• the speed with which regulatory authorizations, pricing approvals and product launches may be achieved;

• whether we can execute on our existing strategic collaborations with respect to our products or product candidates;

• whether and when we will be able to enter into and consummate strategic collaborations with respect to our products or product candidates on acceptable terms;

• the success with which developed products may be commercialized and otherwise accepted by our approved markets;

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• competitive developments affecting our products or product candidates, including generic and branded competition;

• the effect of possible domestic and foreign legislation or regulatory action affecting, among other things, pharmaceutical pricing and reimbursement, including under Medicaid and Medicare in the United States, and involuntary approval of prescription medicines for over-the-counter use and the trend toward managed care and health care cost containment;

• our reliance on third party manufacturers and suppliers;

• our ability to protect our patents and other intellectual property;

• claims and concerns that may arise regarding the safety or efficacy of our products or product candidates;

• governmental laws and regulations affecting our operations, including those affecting taxation; and

• growth in costs and expenses.

The forward-looking statements made or incorporated by reference in this prospectus relate only to events as of the date on which the statements are made. We have included important factors in the cautionary statements included in this prospectus and incorporated herein by reference, including under the caption entitled “Risk Factors” that we believe could cause actual results or events to differ materially from the forward-looking statements that we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures or investments we may make. Except as required by law, we do not assume any intent to update any forward-looking statements after the date on which the statement is made, whether as a result of new information, future events or circumstances or otherwise.

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Description of securities

We or our selling security holders may offer our ordinary shares, each of which may be represented by one American Depositary Share, preference shares, each of which may be represented by one American Depositary Share, various series of senior or subordinated debt securities, warrants to purchase any such securities and any combination of these securities, individually or as units, from time to time under this prospectus at prices and on terms to be determined by market conditions at the time of offering. Each time we or our selling security holders offer a type or series of securities, we will provide a prospectus supplement that will describe the specific amounts, prices and other important terms of the securities.

Description of ordinary shares

In the following summary, a “shareholder” is the person registered in our register of members as the holder of the relevant securities, including ordinary shares that have been deposited in our ADS facility with Citibank, N.A., or the Depositary.

Dividends

Holders of ordinary shares are entitled to receive such dividends as may be declared by the board of directors. All dividends are declared and paid according to the amounts paid up on the shares in respect of which the dividend is paid. To date there have been no dividends paid to holders of ordinary shares.

Any dividend unclaimed after a period of twelve years from the date of declaration of such dividend shall be forfeited and shall revert to us. In addition, the payment by the board of directors of any unclaimed dividend, interest or other sum payable on or in respect of an ordinary share into a separate account shall not constitute us as a trustee in respect thereof.

Rights in a liquidation

Holders of ordinary shares are entitled to participate in any distribution of assets upon a liquidation, subject to prior satisfaction of the claims of creditors and preferential payments to holders of outstanding preference shares.

Voting rights

Voting at any general meeting of shareholders is by a show of hands, unless a poll is demanded. A poll may be demanded by:

• the chairman of the meeting;

• at least two shareholders entitled to vote at the meeting;

• any shareholder or shareholders representing in the aggregate not less than one-tenth of the total voting rights of all shareholders entitled to vote at the meeting; or

• any shareholder or shareholders holding shares conferring a right to vote at the meeting on which there have been paid up sums in the aggregate equal to not less than one-tenth of the total sum paid up on all the shares conferring that right.

In a vote by a show of hands, every shareholder who is present in person or by proxy at a general meeting has one vote. In a vote on a poll, every shareholder who is present in person or by proxy shall have one vote for

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every share of which they are registered as the holder (provided that no shareholder shall have more than one vote on a show of hands notwithstanding that he may have appointed more than one proxy to vote on his behalf). The quorum for a shareholders’ meeting is a minimum of two persons, present in person or by proxy. To the extent our Articles of Association provide for a vote by a show of hands in which each shareholder has one vote, this differs from U.S. law, under which each shareholder typically is entitled to one vote per share at all meetings.

Unless otherwise required by law or our Articles of Association, voting in a general meeting is by ordinary resolution. An ordinary resolution is approved by a majority vote of the shareholders present at a meeting at which there is a quorum. Examples of matters that can be approved by an ordinary resolution include:

• the election of directors;

• the approval of financial statements;

• the declaration of final dividends;

• the appointment of auditors; or

• the grant of authority to issue shares.

A special resolution requires the affirmative vote of not less than three-fourths of the eligible votes of shareholders present at the meeting. Examples of matters that must be approved by a special resolution include modifications to the rights of any class of shares, changes to the Articles of Association, or our winding-up.

Capital calls

The board of directors has the authority to make calls upon the shareholders in respect of any money unpaid on their shares and each shareholder shall pay to us as required by such notice the amount called on his shares. If a call remains unpaid after it has become due and payable, and the fourteen days’ notice provided by the board of directors has not been complied with, any share in respect of which such notice was given may be forfeited by a resolution of the board.

Limitations on ownership

Under English law and our Articles of Association, there are no limitations on the right of nonresidents of the United Kingdom or owners who are not citizens of the United Kingdom to hold or vote our ordinary shares.

Description of preference shares

The following description of our preference shares is only a summary of the general terms of the preference shares of any series that may be offered under this prospectus. We will prepare a prospectus supplement each time we or our selling security holders offer preference shares, which you should read carefully. The prospectus supplement relating to a series of preference shares or to securities that are convertible into or exchangeable for the preference shares will summarize the terms of the preference shares of the particular series. Those terms will be set out in the resolutions establishing the series that our board of directors or an authorized committee adopt, and may be different from those summarized below. If so, the applicable prospectus supplement will so provide, and the description of the preference shares of that series contained in the prospectus supplement will apply. In the following summary, a “shareholder” is the person registered in our register of members as the holder of the preference shares. For those preference shares, if any, that are deposited in an American Depositary Receipt facility pursuant to a deposit agreement, that may be entered into (for additional details see “Description of American Depositary Shares”) with Citibank N.A., the depositary or its nominee is deemed the shareholder.

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Our board of directors has the authority, without further action by shareholders, to issue preference shares, par value £0.05 per share, in one or more series and to fix the rights, preferences, privileges, qualifications and restrictions granted to or imposed upon the preference shares, including dividend rights, conversion rights, voting rights, rights and terms of redemption, and liquidation preference, any or all of which may be greater than the rights of the ordinary shares.

Our board of directors will fix the rights, preferences, privileges, qualifications and restrictions of the preference shares of each series that we or our selling security holders offer under this prospectus and applicable prospectus supplements in the resolutions relating to that series. We will describe the terms of the series of preference shares we or our selling security holders are offering before the issuance of the related series of preference shares in a prospectus supplement. This description will include:

• the title and stated value;

• the number of shares we are offering;

• the liquidation preference per share;

• the purchase price per share;

• the dividend rate per share, dividend period and payment dates and method of calculation for dividends;

• whether dividends will be cumulative or non-cumulative and, if cumulative, the date from which dividends will accumulate;

• our right, if any, to defer payment of dividends and the maximum length of any such deferral period;

• the procedures for any auction and remarketing, if any;

• the provisions for a sinking fund, if any;

• the provisions for redemption or repurchase, if applicable, and any restrictions on our ability to exercise those redemption and repurchase rights;

• any listing of the preference shares on any securities exchange or market;

• whether the preference shares will be convertible into our ordinary shares or other securities of ours, including warrants, and, if applicable, the conversion period, the conversion price, or how it will be calculated, and under what circumstances it may be adjusted;

• whether the preference shares will be exchangeable into debt securities, and, if applicable, the exchange period, the exchange price, or how it will be calculated, and under what circumstances it may be adjusted;

• voting rights, if any, of the preference shares;

• preemption rights, if any;

• restrictions on transfer, sale or other assignment, if any;

• a discussion of any material or special U.S. federal income tax considerations applicable to the preference shares;

• the relative ranking and preferences of the preference shares as to dividend rights and rights if we liquidate, dissolve or wind up our affairs;

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• any limitations on issuances of any class or series of preference shares ranking senior to or on a parity with the series of preference shares being issued as to dividend rights and rights if we liquidate, dissolve or wind up our affairs; and

• any other specific terms, rights, preferences, privileges, qualifications or restrictions of the preference shares.

If we or our selling security holders sell preference shares under this prospectus, the shares will be fully paid and non-assessable.

Our Articles of Association and English law provide that the holders of preference shares will have the right to vote separately as a class on any proposal involving changes that would adversely affect the powers, preferences, or special rights of holders of that series of preference shares.

Description of debt securities

This prospectus describes the general terms and provisions of the debt securities we or our selling security holders may offer under this prospectus. When we or our selling security holders offer to sell a particular series of debt securities, we will describe the specific terms of the securities in a supplement to this prospectus, including any additional covenants or changes to existing covenants relating to such series. The prospectus supplement also will indicate whether the general terms and provisions described in this prospectus apply to a particular series of debt securities. You should read the applicable indenture if you do not fully understand a term or the way we use it in this prospectus.

We or our selling security holders may offer senior or subordinated debt securities. Each series of debt securities may have different terms. The senior debt securities will be issued under one or more senior indentures, dated as of a date prior to such issuance, between us and the trustee identified in the applicable prospectus supplement, as amended or supplemented from time to time. We will refer to any such indenture throughout this prospectus as the “senior indenture.” Any subordinated debt securities will be issued under one or more separate indentures, dated as of a date prior to such issuance, between us and the trustee identified in the applicable prospectus supplement, as amended or supplemented from time to time. We will refer to any such indenture throughout this prospectus as the “subordinated indenture” and to the trustee under the senior or subordinated indenture as the “trustee.” The senior indenture and the subordinated indenture are sometimes collectively referred to in this prospectus as the “indentures.” The indentures will be subject to and governed by the Trust Indenture Act of 1939, as amended. We included copies of the forms of the indentures as exhibits to this registration statement and they are incorporated into this prospectus by reference.

If we issue debt securities at a discount from their principal amount, then, for purposes of calculating the aggregate initial offering price of the offered securities issued under this prospectus, we will include only the initial offering price of the debt securities and not the principal amount of the debt securities.

We have summarized below the material provisions of the indentures and the debt securities, or indicated which material provisions will be described in the related prospectus supplement. The prospectus supplement relating to any particular securities offered will describe the specific terms of the debt securities, which may be in addition to or different from the general terms summarized in this prospectus. Because the summary in this prospectus and in any prospectus supplement does not contain all of the information that you may find useful, you should read the documents relating to the debt securities that are described in this prospectus or in any applicable prospectus supplement. Please read “Where You Can Find More Information” to find out how you can obtain a copy of those documents. Except as otherwise indicated, the terms of the indentures are identical. As used under this caption, the term “debt securities” includes the debt securities being offered by this prospectus and all other debt securities issued by us under the indentures.

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General

The indentures:

• do not limit the amount of debt securities that we may issue;

• allow us to issue debt securities in one or more series;

• do not require us to issue all of the debt securities of a series at the same time;

• allow us to reopen a series to issue additional debt securities without the consent of the holders of the debt securities of such series; and

• provide that the debt securities will be unsecured, except as may be set forth in the applicable prospectus supplement.

Unless we give you different information in the applicable prospectus supplement, the senior debt securities will be unsubordinated obligations and will rank equally with all of our other unsecured and unsubordinated indebtedness. Payments on the subordinated debt securities will be subordinated to the prior payment in full of all of our senior indebtedness, as described under “Description of Debt Securities—Subordination” and in the applicable prospectus supplement.

Each indenture provides that we may, but need not, designate more than one trustee under an indenture. Any trustee under an indenture may resign or be removed and a successor trustee may be appointed to act with respect to the series of debt securities administered by the resigning or removed trustee. If two or more persons are acting as trustee with respect to different series of debt securities, each trustee shall be a trustee of a trust under the applicable indenture separate and apart from the trust administered by any other trustee. Except as otherwise indicated in this prospectus, any action described in this prospectus to be taken by each trustee may be taken by each trustee with respect to, and only with respect to, the one or more series of debt securities for which it is trustee under the applicable indenture.

The prospectus supplement for each offering will provide the following terms, where applicable:

• the title of the debt securities and whether they are senior or subordinated;

• the aggregate principal amount of the debt securities being offered, the aggregate principal amount of the debt securities outstanding as of the most recent practicable date and any limit on their aggregate principal amount, including the aggregate principal amount of debt securities authorized;

• the price at which the debt securities will be issued, expressed as a percentage of the principal and, if other than the principal amount thereof, the portion of the principal amount thereof payable upon declaration of acceleration of the maturity thereof or, if applicable, the portion of the principal amount of such debt securities that is convertible into ordinary shares or preference shares or the method by which any such portion shall be determined;

• if convertible, the terms on which such debt securities are convertible, including the initial conversion price or rate and the conversion period and any applicable limitations on the ownership or transferability of ordinary shares or preference shares received on conversion;

• the date or dates, or the method for determining the date or dates, on which the principal of the debt securities will be payable;

• the fixed or variable interest rate or rates of the debt securities, or the method by which the interest rate or rates is determined;

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• the date or dates, or the method for determining the date or dates, from which interest will accrue;

• the dates on which interest will be payable;

• the record dates for interest payment dates, or the method by which we will determine those dates;

• the persons to whom interest will be payable;

• the basis upon which interest will be calculated if other than that of a 360-day year of twelve 30-day months;

• any make-whole amount, which is the amount in addition to principal and interest that is required to be paid to the holder of a debt security as a result of any optional redemption or accelerated payment of such debt security, or the method for determining the make-whole amount;

• the place or places where the principal of, and any premium, or make-whole amount, and interest on, the debt securities will be payable;

• where the debt securities may be surrendered for registration of transfer or conversion or exchange;

• where notices or demands to or upon us in respect of the debt securities and the applicable indenture may be served;

• the times, prices and other terms and conditions upon which we may redeem the debt securities;

• any obligation we have to redeem, repay or purchase the debt securities pursuant to any sinking fund or analogous provision or at the option of holders of the debt securities, and the times and prices at which we must redeem, repay or purchase the debt securities as a result of such an obligation;

• the currency or currencies in which the debt securities are denominated and payable if other than United States dollars, which may be a foreign currency or units of two or more foreign currencies or a composite currency or currencies and the terms and conditions relating thereto, and the manner of determining the equivalent of such foreign currency in United States dollars;

• whether the principal of, and any premium, or make-whole amount, or interest on, the debt securities of the series are to be payable, at our election or at the election of a holder, in a currency or currencies other than that in which the debt securities are denominated or stated to be payable, and other related terms and conditions;

• whether the amount of payments of principal of, and any premium, or make-whole amount, or interest on, the debt securities may be determined according to an index, formula or other method and how such amounts will be determined;

• whether the debt securities will be in registered form, bearer form or both and (1) if in registered form, the person to whom any interest shall be payable, if other than the person in whose name the security is registered at the close of business on the regular record date for such interest, or (2) if in bearer form, the manner in which, or the person to whom, any interest on the security shall be payable if otherwise than upon presentation and surrender upon maturity;

• any restrictions applicable to the offer, sale or delivery of debt securities in bearer form and the terms upon which securities in bearer form of the series may be exchanged for debt securities in registered form of the series and vice versa if permitted by applicable laws and regulations;

• whether any debt securities of the series are to be issuable initially in temporary global form and whether any debt securities of the series are to be issuable in permanent global form with or without coupons and, if

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so, whether beneficial owners of interests in any such permanent global security may or shall be required to exchange their interests for other debt securities of the series, and the manner in which interest shall be paid;

• the identity of the depositary for securities in registered form, if such series are to be issuable as a global security;

• the date as of which any debt securities in bearer form or in temporary global form shall be dated if other than the original issuance date of the first security of the series to be issued;

• the applicability, if any, of the defeasance and covenant defeasance provisions described in this prospectus or in the applicable indenture;

• whether and under what circumstances we will pay any additional amounts on the debt securities in respect of any tax, assessment or governmental charge and, if so, whether we will have the option to redeem the debt securities in lieu of making such a payment;

• whether and under what circumstances the debt securities being offered are convertible into ordinary shares or preference shares, as the case may be, including the conversion price or rate or the manner of calculation thereof;

• the circumstances, if any, specified in the applicable prospectus supplement, under which beneficial owners of interests in the global security may obtain definitive debt securities and the manner in which payments on a permanent global debt security will be made if any debt securities are issuable in temporary or permanent global form;

• any provisions granting special rights to holders of securities upon the occurrence of such events as specified in the applicable prospectus supplement;

• if the debt securities of such series are to be issuable in definitive form only upon receipt of certain certificates or other documents or satisfaction of other conditions, then the form and/or terms of such certificates, documents or conditions;

• the name of the applicable trustee and the nature of any material relationship between the trustee and us or any of our affiliates, and the percentage of debt securities of the class necessary to require the trustee to take action;

• any deletions from, modifications of, or additions to our events of default or covenants and any change in the right of any trustee or any of the holders to declare the principal amount of any of such debt securities due and payable;

• applicable CUSIP numbers; and

• any other terms of such debt securities not inconsistent with the provisions of the applicable indenture.

We may issue debt securities at a discount below their principal amount and provide for less than the entire principal amount thereof to be payable upon declaration of acceleration of the maturity of the debt securities. We refer to any such debt securities throughout this prospectus as “original issue discount securities.” The applicable prospectus supplement will describe the United States federal income tax consequences and other relevant considerations applicable to original issue discount securities.

We also may issue indexed debt securities. Payments of principal, premium and interest on indexed debt securities are determined with reference to the rate of exchange between the currency or currency unit in

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which the debt security is denominated and any other currency or currency unit specified by us, to the relationship between two or more currencies or currency units or by other similar methods or formulas specified in the prospectus supplement.

Except as described under “—Merger, Consolidation or Sale of Assets” or as may be set forth in any prospectus supplement, the debt securities will not contain any provisions that (1) would limit our ability to incur indebtedness or (2) would afford holders of debt securities protection in the event of (a) a highly leveraged or similar transaction involving us, or (b) a change of control or reorganization, restructuring, merger or similar transaction involving us that may adversely affect the holders of the debt securities. In the future, we may enter into transactions, such as the sale of all or substantially all of our assets or a merger or consolidation, that may have an adverse effect on our ability to service our indebtedness, including the debt securities, by, among other things, substantially reducing or eliminating our assets.

We will provide you with more information in the applicable prospectus supplement regarding any deletions, modifications, or additions to the events of default or covenants that are described below, including any addition of a covenant or other provision providing event risk or similar protection.

Payment

Unless we give you different information in the applicable prospectus supplement, the principal of, and any premium or make-whole amount, and interest on, any series of the debt securities will be payable at the corporate trust office of the trustee. We will provide you with the address of the trustee in the applicable prospectus supplement. We may also pay interest by mailing a check to the address of the person entitled to it as it appears in the applicable register for the debt securities or by wire transfer of funds to that person at an account maintained within the United States.

All monies that we pay to a paying agent or a trustee for the payment of the principal of, and any premium or make-whole amount, or interest on, any debt security will be repaid to us if unclaimed at the end of two years after the obligation underlying payment becomes due and payable. After funds have been returned to us, the holder of the debt security may look only to us for payment, without payment of interest for the period which we hold the funds.

Denomination, interest, registration and transfer

Unless otherwise described in the applicable prospectus supplement, the debt securities of any series will be issuable in denominations of $1,000 and integral multiples of $1,000.

Subject to the limitations imposed upon debt securities that are evidenced by a computerized entry in the records of a depository company rather than by physical delivery of a note, a holder of debt securities of any series may:

• exchange them for any authorized denomination of other debt securities of the same series and of a like aggregate principal amount and kind upon surrender of such debt securities at the corporate trust office of the applicable trustee or at the office of any transfer agent that we designate for such purpose; and

• surrender them for registration of transfer or exchange at the corporate trust office of the applicable trustee or at the office of any transfer agent that we designate for such purpose.

Every debt security surrendered for registration of transfer or exchange must be duly endorsed or accompanied by a written instrument of transfer satisfactory to the applicable trustee or transfer agent. Payment of a service charge will not be required for any registration of transfer or exchange of any debt securities, but we or the

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trustee may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith. If in addition to the applicable trustee, the applicable prospectus supplement refers to any transfer agent initially designated by us for any series of debt securities, we may at any time rescind the designation of any such transfer agent or approve a change in the location through which any such transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for such series. We may at any time designate additional transfer agents for any series of debt securities.

Neither we, nor any trustee, will be required to:

• issue, register the transfer of or exchange debt securities of any series during a period beginning at the opening of business 15 days before the day that the notice of redemption of any debt securities selected for redemption is mailed and ending at the close of business on the day of such mailing;

• register the transfer of or exchange any debt security, or portion thereof, so selected for redemption, in whole or in part, except the unredeemed portion of any debt security being redeemed in part; and

• issue, register the transfer of or exchange any debt security that has been surrendered for repayment at the option of the holder, except the portion, if any, of such debt security not to be so repaid.

Merger, consolidation or sale of assets

The indentures provide that we may, without the consent of the holders of any outstanding debt securities, (1) consolidate with, (2) sell, lease or convey all or substantially all of our assets to, or (3) merge with or into, any other entity provided that:

• either we are the continuing entity, or the successor entity, if other than us, assumes the obligations (A) to pay the principal of, and any premium (or make-whole amount) and interest on, all of the debt securities and (B) to duly perform and observe all of the covenants and conditions contained in each indenture;

• after giving effect to the transaction, there is no event of default under the indentures and no event which, after notice or the lapse of time, or both, would become such an event of default, occurs and continues; and

• an officers’ certificate and legal opinion covering such conditions are delivered to each applicable trustee.

Covenants

Existence. Except as permitted under “—Merger, Consolidation or Sale of Assets,” the indentures require us to do or cause to be done all things necessary to preserve and keep in full force and effect our existence, rights and franchises. However, the indentures do not require us to preserve any right or franchise if we determine that any right or franchise is no longer desirable in the conduct of our business.

Payment of taxes and other claims. The indentures require us to pay, discharge or cause to be paid or discharged, before they become delinquent (1) all taxes, assessments and governmental charges levied or imposed on us, our subsidiaries or our subsidiaries’ income, profits or property, and (2) all lawful claims for labor, materials and supplies which, if unpaid, might by law become a lien upon our property or the property of our subsidiaries. However, we will not be required to pay, discharge or cause to be paid or discharged any such tax, assessment, charge or claim whose amount, applicability or validity is being contested in good faith by appropriate proceedings.

Provision of financial information. The indentures require us to (1) within 15 days of each of the respective dates by which we are required to file our annual reports, quarterly reports and other documents with the SEC, file with the trustee copies of the annual report, quarterly report and other documents that we file with the SEC

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under Section 13 or 15(d) of the Exchange Act of 1934, as amended (the “Exchange Act”), (2) file with the trustee and the SEC any additional information, documents and reports regarding compliance by us with the conditions and covenants of the indentures, as required, (3) within 30 days after the filing with the trustee, mail to all holders of debt securities, as their names and addresses appear in the applicable register for such debt securities, without cost to such holders, summaries of any documents and reports required to be filed by us pursuant to (1) and (2) above, and (4) supply, promptly upon written request and payment of the reasonable cost of duplication and delivery, copies of such documents to any prospective holder.

Additional covenants. The applicable prospectus supplement will set forth any additional covenants of Amarin relating to any series of debt securities.

Events of default, notice and waiver

Unless the applicable prospectus supplement states otherwise, when we refer to “events of default” as defined in the indentures with respect to any series of debt securities, we mean:

• default in the payment of any installment of interest on any debt security of such series continuing for 30 days;

• default in the payment of principal of, or any premium, or make-whole amount, on any debt security of such series for five business days at its stated maturity;

• default in making any sinking fund payment as required for any debt security of such series for five business days;

• default in the performance or breach of any covenant or warranty in the debt securities or in the indenture by us continuing for 60 days after written notice as provided in the applicable indenture, but not of a covenant added to the indenture solely for the benefit of a series of debt securities issued thereunder other than such series;

• a default under any bond, debenture, note, mortgage, indenture or instrument:

(1) having an aggregate principal amount of at least $30,000,000; or

(2) under which there may be issued, secured or evidenced any existing or later created indebtedness for money borrowed by us or our subsidiaries, if we are directly responsible or liable as obligor or guarantor, if the default results in the indebtedness becoming or being declared due and payable prior to the date it otherwise would have, without such indebtedness having been discharged, or such acceleration having been rescinded or annulled, within 30 days after notice to the issuing company specifying such default. Such notice shall be given to us by the trustee, or to us and the trustee by the holders of at least 10% in principal amount of the outstanding debt securities of that series. The written notice specifying such default and requiring us to cause such indebtedness to be discharged or cause such acceleration to be rescinded or annulled and shall state that such notice is a “Notice of Default” under such indenture;

• bankruptcy, insolvency or reorganization, or court appointment of a receiver, liquidator or trustee of Amarin or any significant subsidiary; and

• any other event of default provided with respect to a particular series of debt securities.

When we use the term “significant subsidiary,” we refer to the meaning ascribed to such term in Rule 1-02 of Regulation S-X promulgated under the Securities Act of 1933, as amended, or Securities Act.

If an event of default occurs and is continuing with respect to debt securities of any series outstanding, then the applicable trustee or the holders of 25% or more in principal amount of the debt securities of that series will

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have the right to declare the principal amount of all the debt securities of that series to be due and payable. If the debt securities of that series are original issue discount securities or indexed securities, then the applicable trustee or the holders of 25% or more in principal amount of the debt securities of that series will have the right to declare the portion of the principal amount as may be specified in the terms thereof to be due and payable. However, at any time after such a declaration of acceleration has been made, but before a judgment or decree for payment of the money due has been obtained by the applicable trustee, the holders of at least a majority in principal amount of outstanding debt securities of such series or of all debt securities then outstanding under the applicable indenture may rescind and annul such declaration and its consequences if:

• we have deposited with the applicable trustee all required payments of the principal, any premium, or make-whole amount, interest and, to the extent permitted by law, interest on overdue installment of interest, plus applicable fees, expenses, disbursements and advances of the applicable trustee; and

• all events of default, other than the non-payment of accelerated principal, or a specified portion thereof, and any premium, or make-whole amount, have been cured or waived.

The indentures also provide that the holders of at least a majority in principal amount of the outstanding debt securities of any series or of all debt securities then outstanding under the applicable indenture may, on behalf of all holders, waive any past default with respect to such series and its consequences, except a default:

• in the payment of the principal, any premium, or make-whole amount, or interest;

• in respect of a covenant or provision contained in the applicable indenture that cannot be modified or amended without the consent of the holders of the outstanding debt security that is affected by the default; or

• in respect of a covenant or provision for the benefit or protection of the trustee, without its express written consent.

The indentures require each trustee to give notice to the holders of debt securities within 90 days of a default unless such default has been cured or waived. However, the trustee may withhold notice if specified persons of such trustee consider such withholding to be in the interest of the holders of debt securities. The trustee may not withhold notice of a default in the payment of principal, any premium or interest on any debt security of such series or in the payment of any sinking fund installment in respect of any debt security of such series.

The indentures provide that holders of debt securities of any series may not institute any proceedings, judicial or otherwise, with respect to such indenture or for any remedy under the indenture, unless the trustee fails to act for a period of 60 days after the trustee has received a written request to institute proceedings in respect of an event of default from the holders of 25% or more in principal amount of the outstanding debt securities of such series, as well as an offer of indemnity reasonably satisfactory to the trustee. However, this provision will not prevent any holder of debt securities from instituting suit for the enforcement of payment of the principal of, and any premium, or make-whole amount, and interest on, such debt securities at the respective due dates thereof.

The indentures provide that, subject to provisions in each indenture relating to its duties in the case of a default, a trustee has no obligation to exercise any of its rights or powers at the request or direction of any holders of any series of debt securities then outstanding under the indenture, unless the holders have offered to the trustee reasonable security or indemnity. The holders of at least a majority in principal amount of the outstanding debt securities of any series or of all debt securities then outstanding under an indenture shall have the right to direct the time, method and place of conducting any proceeding for any remedy available to

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the applicable trustee, or of exercising any trust or power conferred upon such trustee. However, a trustee may refuse to follow any direction which:

• is in conflict with any law or the applicable indenture;

• may involve the trustee in personal liability; or

• may be unduly prejudicial to the holders of debt securities of the series not joining the proceeding.

Within 120 days after the close of each fiscal year, we will be required to deliver to each trustee a certificate, signed by one of our several specified officers, stating whether or not that officer has knowledge of any default under the applicable indenture. If the officer has knowledge of any default, the notice must specify the nature and status of the default.

Modification of the indentures

The indentures provide that modifications and amendments may be made only with the consent of the affected holders of at least a majority in principal amount of all outstanding debt securities issued under that indenture. However, no such modification or amendment may, without the consent of the holders of the debt securities affected by the modification or amendment:

• change the stated maturity of the principal of, or any premium, or make-whole amount, on, or any installment of principal of or interest on, any such debt security;

• reduce the principal amount of, the rate or amount of interest on or any premium, or make-whole amount, payable on redemption of any such debt security;

• reduce the amount of principal of an original issue discount security that would be due and payable upon declaration of acceleration of the maturity thereof or would be provable in bankruptcy, or adversely affect any right of repayment of the holder of any such debt security;

• change the place of payment or the coin or currency for payment of principal of, or any premium, or make-whole amount, or interest on, any such debt security;

• impair the right to institute suit for the enforcement of any payment on or with respect to any such debt security;

• reduce the percentage in principal amount of any outstanding debt securities necessary to modify or amend the applicable indenture with respect to such debt securities, to waive compliance with particular provisions thereof or defaults and consequences thereunder or to reduce the quorum or voting requirements set forth in the applicable indenture; or

• modify any of the foregoing provisions or any of the provisions relating to the waiver of particular past defaults or covenants, except to increase the required percentage to effect such action or to provide that some of the other provisions may not be modified or waived without the consent of the holder of such debt security.

The holders of a majority in aggregate principal amount of the outstanding debt securities of each series may, on behalf of all holders of debt securities of that series, waive, insofar as that series is concerned, our compliance with material restrictive covenants of the applicable indenture.

We and our respective trustee may make modifications and amendments of an indenture without the consent of any holder of debt securities for any of the following purposes:

• to evidence the succession of another person to us as obligor under such indenture;

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• to add to our covenants for the benefit of the holders of all or any series of debt securities or to surrender any right or power conferred upon us in such indenture;

• to add events of default for the benefit of the holders of all or any series of debt securities;

• to add or change any provisions of an indenture (1) to change or eliminate restrictions on the payment of principal of, or premium, or make-whole amount, or interest on, debt securities in bearer form, or (2) to permit or facilitate the issuance of debt securities in uncertificated form, provided that such action shall not adversely affect the interests of the holders of the debt securities of any series in any material respect;

• to change or eliminate any provisions of an indenture, provided that any such change or elimination shall become effective only when there are no debt securities outstanding of any series created prior thereto which are entitled to the benefit of such provision;

• to secure the debt securities;

• to establish the form or terms of debt securities of any series;

• to provide for the acceptance of appointment by a successor trustee or facilitate the administration of the trusts under an indenture by more than one trustee;

• to cure any ambiguity, defect or inconsistency in an indenture, provided that such action shall not adversely affect the interests of holders of debt securities of any series issued under such indenture; and

• to supplement any of the provisions of an indenture to the extent necessary to permit or facilitate defeasance and discharge of any series of such debt securities, provided that such action shall not adversely affect the interests of the holders of the outstanding debt securities of any series.

Voting

The indentures provide that in determining whether the holders of the requisite principal amount of outstanding debt securities of a series have given any request, demand, authorization, direction, notice, consent or waiver under the indentures or whether a quorum is present at a meeting of holders of debt securities:

• the principal amount of an original issue discount security that shall be deemed to be outstanding shall be the amount of the principal thereof that would be due and payable as of the date of such determination upon declaration of acceleration of the maturity thereof;

• the principal amount of any debt security denominated in a foreign currency that shall be deemed outstanding shall be the United States dollar equivalent, determined on the issue date for such debt security, of the principal amount or, in the case of an original issue discount security, the United States dollar equivalent on the issue date of such debt security of the amount determined as provided in the preceding bullet point;

• the principal amount of an indexed security that shall be deemed outstanding shall be the principal face amount of such indexed security at original issuance, unless otherwise provided for such indexed security under such indenture; and

• debt securities owned by us or any other obligor upon the debt securities or by any affiliate of ours or of such other obligor shall be disregarded.

The indentures contain provisions for convening meetings of the holders of debt securities of a series. A meeting will be permitted to be called at any time by the applicable trustee, and also, upon request, by us or

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the holders of at least 25% in principal amount of the outstanding debt securities of such series, in any such case upon notice given as provided in such indenture. Except for any consent that must be given by the holder of each debt security affected by the modifications and amendments of an indenture described above, any resolution presented at a meeting or adjourned meeting duly reconvened at which a quorum is present may be adopted by the affirmative vote of the holders of a majority of the aggregate principal amount of the outstanding debt securities of that series represented at such meeting.

Notwithstanding the preceding paragraph, except as referred to above, any resolution relating to a request, demand, authorization, direction, notice, consent, waiver or other action that may be made, given or taken by the holders of a specified percentage, which is less than a majority of the aggregate principal amount of the outstanding debt securities of a series, may be adopted at a meeting or adjourned meeting duly reconvened at which a quorum is present by the affirmative vote of such specified percentage.

Any resolution passed or decision taken at any properly held meeting of holders of debt securities of any series will be binding on all holders of such series. The quorum at any meeting called to adopt a resolution, and at any reconvened meeting, will be persons holding or representing a majority in principal amount of the outstanding debt securities of a series. However, if any action is to be taken relating to a consent or waiver which may be given by the holders of at least a specified percentage in principal amount of the outstanding debt securities of a series, the persons holding such percentage will constitute a quorum.

Notwithstanding the foregoing provisions, the indentures provide that if any action is to be taken at a meeting with respect to any request, demand, authorization, direction, notice, consent, waiver or other action that such indenture expressly provides may be made, given or taken by the holders of a specified percentage in principal amount of all outstanding debt securities affected by such action, or of the holders of such series and one or more additional series:

• there shall be no minimum quorum requirement for such meeting; and

• the principal amount of the outstanding debt securities of such series that vote in favor of such request, demand, authorization, direction, notice, consent, waiver or other action shall be taken account in determining whether such request, demand, authorization, direction, notice, consent, waiver or other action has been made, given or taken under such indenture.

Subordination

Unless otherwise provided in the applicable prospectus supplement and indenture, subordinated securities will be subject to the following subordination provisions.

Upon any distribution to our creditors in a liquidation, dissolution or reorganization, the payment of the principal of and interest on any subordinated securities will be subordinated to the extent provided in the applicable indenture in right of payment to the prior payment in full of all senior debt. However, our obligation to make payments of the principal of and interest on such subordinated securities otherwise will not be affected. No payment of principal or interest will be permitted to be made on subordinated securities at any time if a default on senior debt exists that permits the holders of such senior debt to accelerate its maturity and the default is the subject of judicial proceedings or we receive notice of the default. After all senior debt is paid in full and until the subordinated securities are paid in full, holders of subordinated securities will be subrogated to the rights of holders of senior debt to the extent that distributions otherwise payable to holders of subordinated securities have been applied to the payment of senior debt. The subordinated indenture will not restrict the amount of senior debt or other indebtedness of Amarin and its subsidiaries. As a result of these subordination provisions, in the event of a distribution of assets upon insolvency, holders of subordinated securities may recover less, ratably, than our general creditors.

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The term “senior debt” will be defined in the applicable indenture as the principal of and interest on, or substantially similar payments to be made by us in respect of, other outstanding indebtedness, whether outstanding at the date of execution of the applicable indenture or subsequently incurred, created or assumed. The prospectus supplement may include a description of additional terms implementing the subordination feature.

No restrictions will be included in any indenture relating to subordinated securities upon the creation of additional senior debt.

If this prospectus is being delivered in connection with the offering of a series of subordinated securities, the accompanying prospectus supplement or the information incorporated in this prospectus by reference will set forth the approximate amount of senior debt outstanding as of the end of our most recent fiscal quarter.

Discharge, defeasance and covenant defeasance

Unless otherwise indicated in the applicable prospectus supplement, the indentures allow us to discharge our obligations to holders of any series of debt securities issued under any indenture when:

• either (1) all securities of such series have already been delivered to the applicable trustee for cancellation; or (2) all securities of such series have not already been delivered to the applicable trustee for cancellation but (A) have become due and payable, (B) will become due and payable within one year, or (C) if redeemable at our option, are to be redeemed within one year, and we have irrevocably deposited with the applicable trustee, in trust, funds in such currency or currencies, currency unit or units or composite currency or currencies in which such debt securities are payable, an amount sufficient to pay the entire indebtedness on such debt securities in respect of principal and any premium, or make-whole amount, and interest to the date of such deposit if such debt securities have become due and payable or, if they have not, to the stated maturity or redemption date;

• we have paid or caused to be paid all other sums payable; and

• an officers’ certificate and an opinion of counsel stating the conditions to discharging the debt securities have been satisfied have been delivered to the trustee.

Unless otherwise indicated in the applicable prospectus supplement, the indentures provide that, upon our irrevocable deposit with the applicable trustee, in trust, of an amount, in such currency or currencies, currency unit or units or composite currency or currencies in which such debt securities are payable at stated maturity, or government obligations, or both, applicable to such debt securities, which through the scheduled payment of principal and interest in accordance with their terms will provide money in an amount sufficient to pay the principal of, and any premium, or make-whole amount, and interest on, such debt securities, and any mandatory sinking fund or analogous payments thereon, on the scheduled due dates therefor, the issuing company may elect either:

• to defease and be discharged from any and all obligations with respect to such debt securities; or

• to be released from its obligations with respect to such debt securities under the applicable indenture or, if provided in the applicable prospectus supplement, its obligations with respect to any other covenant, and any omission to comply with such obligations shall not constitute an event of default with respect to such debt securities.

Notwithstanding the above, we may not elect to defease and be discharged from the obligation to pay any additional amounts upon the occurrence of particular events of tax, assessment or governmental charge with respect to payments on such debt securities and the obligations to register the transfer or exchange of such

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debt securities, to replace temporary or mutilated, destroyed, lost or stolen debt securities, to maintain an office or agency in respect of such debt securities, or to hold monies for payment in trust.

The indentures only permit us to establish the trust described in the paragraph above if, among other things, it has delivered to the applicable trustee an opinion of counsel to the effect that the holders of such debt securities will not recognize income, gain or loss for United States federal income tax purposes as a result of such defeasance or covenant defeasance and will be subject to United States federal income tax on the same amounts, in the same manner and at the same times as would have been the case if such defeasance or covenant defeasance had not occurred. Such opinion of counsel, in the case of defeasance, will be required to refer to and be based upon a ruling received from or published by the Internal Revenue Service or a change in applicable United States federal income tax law occurring after the date of the indenture. In the event of such defeasance, the holders of such debt securities would be able to look only to such trust fund for payment of principal, any premium, or make-whole amount, and interest.

When we use the term “government obligations,” we mean securities that are:

• direct obligations of the United States or the government that issued the foreign currency in which the debt securities of a particular series are payable, for the payment of which its full faith and credit is pledged; or

• obligations of a person controlled or supervised by and acting as an agency or instrumentality of the United States or other government that issued the foreign currency in which the debt securities of such series are payable, the payment of which is unconditionally guaranteed as a full faith and credit obligation by the United States or such other government, which are not callable or redeemable at the option of the issuer thereof and shall also include a depository receipt issued by a bank or trust company as custodian with respect to any such government obligation or a specific payment of interest on or principal of any such government obligation held by such custodian for the account of the holder of a depository receipt. However, except as required by law, such custodian is not authorized to make any deduction from the amount payable to the holder of such depository receipt from any amount received by the custodian in respect of the government obligation or the specific payment of interest on or principal of the government obligation evidenced by such depository receipt.

Unless otherwise provided in the applicable prospectus supplement, if after we have deposited funds and/or government obligations to effect defeasance or covenant defeasance with respect to debt securities of any series, (1) the holder of a debt security of such series is entitled to, and does, elect under the terms of the applicable indenture or the terms of such debt security to receive payment in a currency, currency unit or composite currency other than that in which such deposit has been made in respect of such debt security, or (2) a conversion event occurs in respect of the currency, currency unit or composite currency in which such deposit has been made, the indebtedness represented by such debt security will be deemed to have been, and will be, fully discharged and satisfied through the payment of the principal of, and premium, or make-whole amount, and interest on, such debt security as they become due out of the proceeds yielded by converting the amount so deposited in respect of such debt security into the currency, currency unit or composite currency in which such debt security becomes payable as a result of such election or such cessation of usage based on the applicable market exchange rate.

When we use the term “conversion event,” we mean the cessation of use of:

• a currency, currency unit or composite currency both by the government of the country that issued such currency and for the settlement of transactions by a central bank or other public institutions of or within the international banking community;

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• the European Currency Unit (as defined and revised from time to time by the Council of the European Communities) both within the European Monetary System (as defined in the applicable indenture) and for the settlement of transactions by public institutions of or within the European Communities; or

• any currency unit or composite currency other than the European Currency Unit for the purposes for which it was established.

Unless otherwise provided in the applicable prospectus supplement, all payments of principal of, and any premium, or make-whole amount, and interest on, any debt security that is payable in a foreign currency that ceases to be used by its government of issuance shall be made in United States dollars.

In the event that (1) we effect covenant defeasance with respect to any debt securities and (2) those debt securities are declared due and payable because of the occurrence of any event of default, the amount in the currency, currency unit or composite currency in which such debt securities are payable, and government obligations on deposit with the applicable trustee, will be sufficient to pay amounts due on such debt securities at the time of their stated maturity but may not be sufficient to pay amounts due on such debt securities at the time of the acceleration resulting from such event of default. However, the issuing company would remain liable to make payments of any amounts due at the time of acceleration.

The applicable prospectus supplement may further describe the provisions, if any, permitting such defeasance or covenant defeasance, including any modifications to the provisions described above, with respect to the debt securities of or within a particular series.

Conversion rights

The terms and conditions, if any, upon which the debt securities are convertible into ordinary shares or preference shares will be set forth in the applicable prospectus supplement. The terms will include whether the debt securities are convertible into ordinary shares or preference shares, the conversion price, or manner of calculation thereof, the conversion period, provisions as to whether conversion will be at the issuing company’s option or the option of the holders, the events requiring an adjustment of the conversion price and provisions affecting conversion in the event of the redemption of the debt securities and any restrictions on conversion.

Global securities

The debt securities of a series may be issued in whole or in part in the form of one or more global securities that will be deposited with, or on behalf of, a depository identified in the applicable prospectus supplement relating to such series. Global securities, if any, issued in the United States are expected to be deposited with The Depository Trust Company, or DTC, as depository. We may issue global securities in either registered or bearer form and in either temporary or permanent form. We will describe the specific terms of the depository arrangement with respect to a series of debt securities in the applicable prospectus supplement relating to such series. We expect that unless the applicable prospectus supplement provides otherwise, the following provisions will apply to depository arrangements.

Once a global security is issued, the depository for such global security or its nominee will credit on its book-entry registration and transfer system the respective principal amounts of the individual debt securities represented by such global security to the accounts of participants that have accounts with such depository. Such accounts shall be designated by the underwriters, dealers or agents with respect to such debt securities or by us if we offer such debt securities directly. Ownership of beneficial interests in such global security will be limited to participants with the depository or persons that may hold interests through those participants.

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We expect that, under procedures established by DTC, ownership of beneficial interests in any global security for which DTC is the depository will be shown on, and the transfer of that ownership will be effected only through, records maintained by DTC or its nominee, with respect to beneficial interests of participants with the depository, and records of participants, with respect to beneficial interests of persons who hold through participants with the depository. Neither we nor the trustee will have any responsibility or liability for any aspect of the records of DTC or for maintaining, supervising or reviewing any records of DTC or any of its participants relating to beneficial ownership interests in the debt securities. The laws of some states require that certain purchasers of securities take physical delivery of such securities in definitive form. Such limits and laws may impair the ability to own, pledge or transfer beneficial interest in a global security.

So long as the depository for a global security or its nominee is the registered owner of such global security, such depository or such nominee, as the case may be, will be considered the sole owner or holder of the debt securities represented by the global security for all purposes under the applicable indenture. Except as described below or in the applicable prospectus supplement, owners of beneficial interest in a global security will not be entitled to have any of the individual debt securities represented by such global security registered in their names, will not receive or be entitled to receive physical delivery of any such debt securities in definitive form and will not be considered the owners or holders thereof under the applicable indenture. Beneficial owners of debt securities evidenced by a global security will not be considered the owners or holders thereof under the applicable indenture for any purpose, including with respect to the giving of any direction, instructions or approvals to the trustee under the indenture. Accordingly, each person owning a beneficial interest in a global security with respect to which DTC is the depository must rely on the procedures of DTC and, if such person is not a participant with the depository, on the procedures of the participant through which such person owns its interests, to exercise any rights of a holder under the applicable indenture. We understand that, under existing industry practice, if DTC requests any action of holders or if an owner of a beneficial interest in a global security desires to give or take any action which a holder is entitled to give or take under the applicable indenture, DTC would authorize the participants holding the relevant beneficial interest to give or take such action, and such participants would authorize beneficial owners through such participants to give or take such actions or would otherwise act upon the instructions of beneficial owners holding through them.

Payments of principal of, and any premium, or make-whole amount, and interest on, individual debt securities represented by a global security registered in the name of a depository or its nominee will be made to or at the direction of the depository or its nominee, as the case may be, as the registered owner of the global security under the applicable indenture. Under the terms of the applicable indenture, we and the trustee may treat the persons in whose name debt securities, including a global security, are registered as the owners thereof for the purpose of receiving such payments. Consequently, neither we nor the trustee have or will have any responsibility or liability for the payment of such amounts to beneficial owners of debt securities including principal, any premium, or make-whole amount, or interest. We believe, however, that it is currently the policy of DTC to immediately credit the accounts of relevant participants with such payments, in amounts proportionate to their respective holdings of beneficial interests in the relevant global security as shown on the records of DTC or its nominee. We also expect that payments by participants to owners of beneficial interests in such global security held through such participants will be governed by standing instructions and customary practices, as is the case with securities held for the account of customers in bearer form or registered in street name, and will be the responsibility of such participants. Redemption notices with respect to any debt securities represented by a global security will be sent to the depository or its nominee. If less than all of the debt securities of any series are to be redeemed, we expect the depository to determine the amount of the interest of each participant in such debt securities to be redeemed to be determined by lot. Neither we, the trustee, any paying agent nor the security registrar for such debt securities will have any responsibility or liability for any aspect of the records relating to or payments made on account of beneficial ownership interests in the global security for such debt securities or for maintaining any records with respect thereto.

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Neither we nor the trustee will be liable for any delay by the holders of a global security or the depository in identifying the beneficial owners of debt securities, and we and the trustee may conclusively rely on, and will be protected in relying on, instructions from the holder of a global security or the depository for all purposes. The rules applicable to DTC and its participants are on file with the SEC.

If a depository for any debt securities is at any time unwilling, unable or ineligible to continue as depository and we do not appoint a successor depository within 90 days, we will issue individual debt securities in exchange for the global security representing such debt securities. In addition, we may at any time and in our sole discretion, subject to any limitations described in the applicable prospectus supplement relating to such debt securities, determine not to have any of such debt securities represented by one or more global securities and in such event will issue individual debt securities in exchange for the global security or securities representing such debt securities. Individual debt securities so issued will be issued in denominations of $1,000 and integral multiples of $1,000.

The debt securities of a series may also be issued in whole or in part in the form of one or more bearer global securities that will be deposited with a depository, or with a nominee for such depository, identified in the applicable prospectus supplement. Any such bearer global securities may be issued in temporary or permanent form. The specific terms and procedures, including the specific terms of the depositary arrangement, with respect to any portion of a series of debt securities to be represented by one or more bearer global securities will be described in the applicable prospectus supplement.

No recourse

There is no recourse under any obligation, covenant or agreement in the applicable indenture or with respect to any security against any of our or our successor’s past, present or future stockholders, employees, officers or directors.

Description of warrants

We or our selling security holders may offer warrants for the purchase of ordinary shares, each of which may be represented by one American Depositary Share, preference shares, each of which may be represented by one or more American Depositary Share, and/or senior or subordinated debt securities in one or more series, from time to time. We may issue warrants independently or together with ordinary shares, each of which may be represented by one American Depositary Share, preference shares, each of which may be represented by one American Depositary Share, and/or senior or subordinated debt securities, and the warrants may be attached to or separate from those securities.

If we or our selling security holders offer warrants, they will be evidenced by warrant certificates issued under one or more warrant agreements, which are contracts between us and an agent for the holders of the warrants. We urge you to read the prospectus supplement related to any series of warrants we may offer, as well as the complete warrant agreement and warrant certificate that contain the terms of the warrants. If we or our selling security holders offer warrants, forms of warrant agreements and warrant certificates relating to warrants for the purchase of such ordinary shares, preference shares and debt securities will be incorporated by reference into the registration statement of which this prospectus is a part from reports we would subsequently file with the SEC.

Description of American Depositary Shares

Citibank, N.A. acts as the depositary bank for ADSs, which we also refer to as the Depositary. Citibank’s depositary offices are located at 388 Greenwich Street, New York, New York 10013. American Depositary Shares

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are frequently referred to as “ADSs” and represent ownership interests in securities that are on deposit with the depositary bank. ADSs may be represented by certificates that are commonly known as “American Depositary Receipts” or “ADRs.” The Depositary typically appoints a custodian to safekeep the securities on deposit. In this case, the custodian is Citibank, N.A., London Branch, having its principal office at Citigroup Centre, Canada Square, Canary Wharf, London E14 5LB, England.

We have appointed Citibank as the Depositary for the ADSs pursuant to an amended and restated deposit agreement dated as of November 4, 2011. A copy of the deposit agreement is on file with the SEC under cover of a Registration Statement on Form F-6 filed on September 16, 2011. You may obtain a copy of the deposit agreement from the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549 and from the SEC’s website (www.sec.gov). Please refer to Registration Number 333-176898 or 333-213106 when retrieving such copy.

We are providing you with a summary description of the material terms of the ADSs and of the material rights of the holders of ADSs. Please remember that summaries by their nature lack the precision of the information summarized and that the rights and obligations of a holder of ADSs will be determined by reference to the terms of the deposit agreement and not by this summary. Holders should review the deposit agreement in its entirety.

Each ADS represents the right to receive one ordinary share on deposit with the custodian. An ADS also represents the right to receive any other property received by the depositary bank or the custodian on behalf of the owner of the ADS but that has not been distributed to the owners of ADSs because of legal restrictions or practical considerations. The custodian, the depositary bank and their respective nominees will hold all deposited property for the benefit of the holders and beneficial owners of ADSs. The deposited property does not constitute the proprietary assets of the depositary bank, the custodian or their nominees. Beneficial ownership in the deposited property will under the terms of the deposit agreement be vested in the beneficial owners of the ADSs. The depositary bank, the custodian and their respective nominees will be the record holders of the deposited property represented by the ADSs for the benefit of the holders and beneficial owners of the corresponding ADSs. Owners of ADSs will be able to exercise beneficial ownership interests in the deposited property only through the registered holders of the ADSs, by the registered holders of the ADSs (on behalf of the applicable ADS owners) only through the depositary bank, and by the depositary bank (on behalf of the owners of the corresponding ADSs) directly, or indirectly through the custodian or their respective nominees, in each case upon the terms of the deposit agreement.

If you become an owner of ADSs, you will become a party to the deposit agreement and therefore will be bound to its terms and to the terms of any ADR that represents your ADSs. The deposit agreement and the ADR specify our rights and obligations as well as your rights and obligations as owner of ADSs and those of the depositary bank. As an ADS holder you appoint the depositary bank to act on your behalf in certain circumstances. The deposit agreement and the ADRs are governed by New York law. However, our obligations to the holders of ordinary shares will continue to be governed by the laws of England and Wales, which may be different from the laws in the United States.

A holder of ADSs may hold its ADSs either by means of an ADR registered in its name, through a brokerage or safekeeping account, or through an account established by the depositary bank in its name reflecting the registration of uncertificated ADSs directly on the books of the depositary bank (commonly referred to as the “direct registration system” or “DRS”). The direct registration system reflects the uncertificated (book-entry) registration of ownership of ADSs by the depositary bank. Under the direct registration system, ownership of ADSs is evidenced by periodic statements issued by the depositary bank to the holders of the ADSs. The direct registration system includes automated transfers between the depositary bank and The Depository Trust Company, or DTC, the central book-entry clearing and settlement system for equity securities in the United

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States. If the ADSs are held through your brokerage or safekeeping account, you must rely on the procedures of your broker or bank to assert your rights as ADS owner. Banks and brokers typically hold securities such as the ADSs through clearing and settlement systems such as DTC. The procedures of such clearing and settlement systems may limit your ability to exercise your rights as an owner of ADSs. Please consult with your broker or bank if you have any questions concerning these limitations and procedures. All ADSs held through DTC will be registered in the name of a nominee of DTC. This summary description assumes you have opted to own the ADSs directly by means of an ADS registered in your name and, as such, we will refer to you as the “holder.” When we refer to “you,” we assume the reader owns ADSs and will own ADSs at the relevant time.

Dividends and distributions

As a holder of ADSs, you generally have the right to receive the distributions we make on the securities deposited with the custodian. Your receipt of these distributions may be limited, however, by practical considerations and legal limitations. Holders of ADSs will receive such distributions under the terms of the deposit agreement, in proportion to the number of ADSs held as of a specified record date, after deduction of applicable fees, taxes and expenses.

Distributions of cash

If we make a cash distribution for the securities on deposit with the custodian, we will deposit the funds with the custodian. Upon receipt of confirmation of the deposit of the requisite funds, the Depositary will arrange for the funds to be converted into U.S. dollars and for the distribution of the U.S. dollars to the holders, subject to applicable laws and regulations.

The conversion into U.S. dollars will take place only if practicable and if the U.S. dollars are transferable to the United States. The Depositary will apply the same method for distributing the proceeds of the sale of any deposited property (such as undistributed rights) held by the Depositary or the custodian in respect of ADSs.

The distribution of cash will be made net of the fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. The Depositary will hold any cash amounts it is unable to distribute in a non-interest bearing account for the benefit of the applicable holders and beneficial owners of ADSs until the distribution can be effected or the funds that the Depositary holds must be escheated as unclaimed property in accordance with the laws of the relevant states of the United States.

Distributions of shares

Whenever we make a free distribution of shares for the securities on deposit with the Depositary or the custodian, we will deposit the applicable number of shares with the Depositary or the custodian. Upon receipt of confirmation of such deposit, the Depositary will either distribute to holders new ADSs representing the ordinary shares deposited or modify the ADS-to-shares ratio, in which case each ADS you hold will represent rights and interests in the additional ordinary shares so deposited. Only whole new ADSs will be distributed. Fractional entitlements will be sold and the proceeds of such sale will be distributed as in the case of a cash distribution.

The distribution of new ADSs or the modification of the ADS-to-ordinary shares ratio upon a distribution of ordinary shares will be made net of the fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement, as applicable. In order to pay such taxes or governmental charges, the Depositary may sell all or a portion of the new ordinary shares so distributed.

No such distribution of new ADSs will be made if it would violate a law (i.e., the U.S. securities laws) or if it is not operationally practicable. If the Depositary does not distribute new ADSs as described above, it may sell the

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shares received upon the terms described in the deposit agreement, as applicable, and will distribute the proceeds of the sale as in the case of a distribution of cash.

Distributions of rights

Whenever we intend to distribute rights to purchase additional ordinary shares, we will give prior notice to the Depositary, indicate to the Depositary whether we wish to make such distributions available to holders of ADSs and assist the Depositary in determining whether it is lawful and reasonably practicable to distribute rights to purchase additional ADSs to holders.

The Depositary will establish procedures to distribute rights to purchase additional ADSs to holders and to enable such holders to exercise such rights if it is lawful and reasonably practicable to make the rights available to holders of ADSs, and if we provide all of the documentation contemplated in the deposit agreement, as applicable (such as opinions to address the lawfulness of the transaction). You may have to pay fees, expenses, taxes and other governmental charges to subscribe for the new ADSs upon the exercise of your rights. The Depositary is not obligated to establish procedures to facilitate the distribution and exercise by holders of rights to purchase new ordinary shares other than in the form of ADSs.

The Depositary will not distribute the rights to you if:

• We do not request that the rights be distributed to you or we request that the rights not be distributed to you; or

• We fail to deliver satisfactory documents to the Depositary; or

• It is not reasonably practicable to distribute the rights.

The Depositary will sell the rights that are not exercised or not distributed if such sale is lawful and reasonably practicable. The proceeds of such sale will be distributed to holders as in the case of a cash distribution. If the Depositary is unable to sell the rights, it will allow the rights to lapse.

Elective distributions

Whenever we intend to distribute a dividend payable at the election of shareholders either in cash or in additional shares, we will give prior notice thereof to the Depositary and will indicate whether we wish the elective distribution to be made available to you. In such case, we will assist the Depositary in determining whether such distribution is lawful and reasonably practicable.

The Depositary will make the election available to you only if it is reasonably practicable and if we have provided all of the documentation contemplated in the deposit agreement, as applicable, and indicate to the Depositary that we wish the elective distributions be made available to you. In such case, the Depositary will establish procedures to enable you to elect to receive either cash or additional ADSs, in each case as described in the deposit agreement, as applicable.

If the election is not made available to you, you will receive either cash or additional ADSs, depending on what a shareholder under English law would receive upon failing to make an election, as more fully described in the deposit agreement, as applicable.

Other distributions

Whenever we intend to distribute property other than cash, ordinary shares or rights to purchase additional ordinary shares, we will notify the Depositary in advance and will indicate whether we wish such distribution to be made to you. If so, we will assist the Depositary in determining whether such distribution to holders is lawful and reasonably practicable.

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If it is reasonably practicable to distribute such property to you and if we provide all of the documentation contemplated in the deposit agreement, as applicable, the Depositary will distribute the property to the holders in a manner it deems practicable.

The distribution will be made net of fees, expenses, taxes and governmental charges payable by holders under the terms of the deposit agreement. In order to pay such taxes and governmental charges, the Depositary may sell all or a portion of the property received.

The Depositary will not distribute the property to you and will sell the property if:

• We do not request that the property be distributed to you or if we ask that the property not be distributed to you; or

• We do not deliver satisfactory documents to the Depositary; or

• The Depositary determines that all or a portion of the distribution to you is not reasonably practicable.

The proceeds of such a sale will be distributed to holders as in the case of a cash distribution.

Redemption

Whenever we decide to redeem any of the securities on deposit with the custodian, we will notify the Depositary in advance. If it is practicable and if we provide all of the documentation contemplated in the deposit agreement, the Depositary will provide notice of the redemption to the holders.

The custodian will be instructed to surrender the shares being redeemed against payment of the applicable redemption price. You may have to pay fees, expenses, taxes and other governmental charges upon the redemption of your ADSs. If less than all ADSs are being redeemed, the ADSs to be retired will be selected by lot or on a pro rata basis, as the Depositary may determine.

Changes affecting shares

The shares held on deposit for your ADSs may change from time to time. For example, there may be a change in nominal or par value, a split-up, cancellation, consolidation or reclassification of such shares or a recapitalization, reorganization, merger, consolidation or sale of assets.

If any such change were to occur, your ADSs would, to the extent permitted by law, represent the right to receive the property received or exchanged in respect of the shares held on deposit. The Depositary may in such circumstances deliver new ADSs to you, call for the exchange of your existing ADSs for new ADSs and take any other actions that are appropriate to reflect as to the ADSs the change affecting the shares. If the Depositary may not lawfully distribute such property to you, the Depositary may sell such property and distribute the net proceeds to you as in the case of a cash distribution.

Transfer, combination and split up of ADRs

As an ADR holder, you will be entitled to transfer, combine or split up your ADRs and the ADSs evidenced thereby. For transfers of ADRs, you will have to surrender the ADRs to be transferred to the Depositary and also must:

• ensure that the surrendered ADR is properly endorsed or otherwise in proper form for transfer;

• provide such proof of identity and genuineness of signatures as the Depositary deems appropriate;

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• provide any transfer stamps required by the State of New York or the United States; and

• pay all applicable fees, charges, expenses, taxes and other government charges payable by ADR holders pursuant to the terms of the deposit agreement, upon the transfer of ADRs.

To have your ADRs either combined or split up, you must surrender the ADRs in question to the Depositary with your request to have them combined or split up, and you must pay all applicable fees, charges and expenses payable by ADR holders, pursuant to the terms of the deposit agreement, upon a combination or split up of ADRs.

Withdrawal of shares upon cancellation of ADSs

As an ADS holder, you will be entitled to present your ADSs to the Depositary for cancellation and then receive the corresponding number of underlying ordinary shares or other deposited securities at the custodian’s offices. Your ability to withdraw the ordinary shares may be limited by U.S. and U.K. legal considerations applicable at the time of withdrawal. In order to withdraw the ordinary shares represented by your ADSs, you will be required to pay to the Depositary the fees for cancellation of ADSs and any charges and taxes payable upon the transfer of the ordinary shares being withdrawn. You assume the risk for delivery of all funds and securities upon withdrawal. Once canceled, the ADSs will not have any rights under the deposit agreement.

If you hold ADSs registered in your name, the Depositary may ask you to provide proof of identity and genuineness of any signature and such other documents as the Depositary may deem appropriate before it will cancel your ADSs. The withdrawal of the shares represented by your ADSs may be delayed until the Depositary receives satisfactory evidence of compliance with all applicable laws and regulations. Please keep in mind that the Depositary will only accept ADSs for cancellation that represent a whole number of securities on deposit.

You will have the right to withdraw the securities represented by your ADSs at any time except for:

• Temporary delays that may arise because (i) the transfer books for the ordinary shares or ADSs are closed, or (ii) shares are immobilized on account of a shareholders’ meeting or a payment of dividends.

• Obligations to pay fees, taxes and similar charges.

• Restrictions imposed because of laws or regulations applicable to ADSs or the withdrawal of securities on deposit.

The deposit agreement may not be modified to impair your right to withdraw the securities represented by your ADSs except to comply with mandatory provisions of law.

Voting rights

As a holder of ADSs, you generally have the right under the deposit agreement to instruct the Depositary to exercise the voting rights for the ordinary shares represented by your ADSs. The voting rights of holders of ordinary shares are described under the heading “Description of Securities–Description of Ordinary Shares”.

At our request, the Depositary will distribute to you any notice of shareholders’ meeting received from us together with information explaining how to instruct the Depositary to exercise the voting rights of the securities represented by ADSs.

If the Depositary timely receives voting instructions from a holder of ADSs, it will endeavor to vote the securities (in person or by proxy) represented by the holder’s ADSs in accordance with such voting instructions, provided that if such timely received instructions fail to specify the manner in which the Depositary is to vote, such holder shall be deemed to have instructed the Depositary to vote in favor if the items set forth in such instructions.

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Please note that the ability of the Depositary to carry out voting instructions may be limited by practical and legal limitations and the terms of the securities on deposit. We cannot assure you that you will receive voting materials in time to enable you to return voting instructions to the Depositary in a timely manner. Securities for which no voting instructions have been received will not be voted.

Fees and charges

As an ADS holder, you will be required to pay the following service fees to the Depositary:

Service		Fees
•	Issuance of ADSs upon deposit of Shares (excluding issuances as a result of distributions described in the fourth paragraph below).	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) issued.
•	Delivery of Deposited Securities against surrender of ADSs.	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) surrendered.
•	Distribution of cash dividends or other cash distributions (i.e., sale of rights and other entitlements).	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) held.
•	Distribution of ADSs pursuant to (i) stock dividends or other free stock distributions, or (ii) exercise of rights to purchase additional ADSs.	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) held.
•	Distribution of securities other than ADSs or rights to purchase additional ADSs (i.e., spin-off shares).	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) held.
•	Depositary Services.	Up to U.S. $5.00 per 100 ADSs (or fraction thereof) held on the applicable record date(s) established by the Depositary.

As an ADS holder you will also be responsible to pay certain fees and expenses incurred by the Depositary and certain taxes and governmental charges such as:

• Fees for the transfer and registration of shares charged by the registrar and transfer agent for the shares in England (i.e., upon deposit and withdrawal of ordinary shares).

• Expenses incurred for converting foreign currency into U.S. dollars.

• Expenses for cable, telex and fax transmissions and for delivery of securities.

• Taxes and duties upon the transfer of securities (i.e., when ordinary shares are deposited or withdrawn from deposit).

• Fees and expenses incurred in connection with the delivery or servicing of ordinary shares on deposit.

Depositary fees payable upon the issuance and cancellation of ADSs are typically paid to the Depositary by the brokers (on behalf of their clients) receiving the newly issued ADSs from the Depositary and by the brokers (on behalf of their clients) delivering the ADSs to the Depositary for cancellation. The brokers in turn charge these fees to their clients. Depositary fees payable in connection with distributions of cash or securities to ADS holders and the depositary services fee are charged by the Depositary to the holders of record of ADSs as of the applicable ADS record date.

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The Depositary fees payable for cash distributions are generally deducted from the cash being distributed. In the case of distributions other than cash (i.e., stock dividend, rights), the Depositary charges the applicable fee to the ADS record date holders concurrent with the distribution. In the case of ADSs registered in the name of the investor (whether certificated or uncertificated in direct registration), the Depositary sends invoices to the applicable record date ADS holders. In the case of ADSs held in brokerage and custodian accounts (via DTC), the Depositary generally collects its fees through the systems provided by DTC (whose nominee is the registered holder of the ADSs held in DTC) from the brokers and custodians holding ADSs in their DTC accounts. The brokers and custodians who hold their clients’ ADSs in DTC accounts in turn charge their clients’ accounts the amount of the fees paid to the Depositary.

In the event of refusal to pay the depositary fees, the Depositary may, under the terms of the deposit agreement, refuse the requested service until payment is received or may set off the amount of the depositary fees from any distribution to be made to the ADS holder.

Note that the fees and charges you may be required to pay may vary over time and may be changed by us and by the Depositary. You will receive prior notice of such changes.

The Depositary may reimburse us for certain expenses incurred by us in respect of the ADR program established pursuant to the deposit agreement, by making available a portion of the depositary fees charged in respect of the ADR program or otherwise, upon such terms and conditions as we and the Depositary may agree from time to time.

Amendments and termination

We may agree with the Depositary to modify the deposit agreement or any ADR at any time without your consent. We undertake to give holders 30 days’ prior notice of any modifications that would materially prejudice any of their substantial rights under the deposit agreement. We will not consider to be materially prejudicial to your substantial rights any modifications or supplements that are reasonably necessary for the ADSs to be registered under the Securities Act or to be eligible for book-entry settlement, in each case without imposing or increasing the fees and charges you are required to pay. In addition, we may not be able to provide you with prior notice of any modifications or supplements that are required to accommodate compliance with applicable provisions of law.

You will be bound by the modifications to the deposit agreement or any ADR if you continue to hold your ADSs after the modifications to such agreement or any ADR become effective. Neither the deposit agreement nor any ADR can be amended to prevent you from withdrawing the securities represented by your ADSs (except in order to comply with applicable law).

We have the right to direct the Depositary to terminate the deposit agreement. Similarly, the Depositary may in certain circumstances on its own initiative terminate the deposit agreement. In either case, the Depositary must give notice to the holders at least 30 days before termination. Until termination, your rights under either agreement will be unaffected.

After termination, the Depositary will continue to collect distributions received (but will not distribute any such property until you request the cancellation of your ADSs) and may sell the securities held on deposit. After the sale, the Depositary will hold the proceeds from such sale and any other funds then held for the holders of ADSs in a non-interest bearing account. At that point, the Depositary will have no further obligations to holders other than to account for the funds then held for the holders of ADSs still outstanding (after deduction of applicable fees, taxes and expenses).

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Books of depositary

The Depositary will maintain ADS holder records at its depositary office. You may inspect such records at such office during regular business hours but solely for the purpose of communicating with other holders in the interest of business matters relating to the ADSs and the deposit agreement.

The Depositary will maintain in New York facilities to record and process the issuance, cancellation, combination, split-up and transfer of ADSs. These facilities may be closed from time to time, to the extent not prohibited by law.

Limitations on obligations and liabilities

The deposit agreement limits our obligations and the Depositary’s obligations to you. Please note the following:

• We and the Depositary are obligated only to take the actions specifically stated in the deposit agreement, as applicable, without negligence or bad faith.

• The Depositary disclaims any liability for any failure to carry out voting instructions, for any manner in which a vote is cast or for the effect of any vote, provided it acts in good faith and in accordance with the terms of the deposit agreement, as applicable.

• The Depositary disclaims any liability for any failure to determine the lawfulness or practicality of any action, for the content of any document forwarded to you on our behalf or for the accuracy of any translation of such a document, for the investment risks associated with investing in ordinary shares or other deposited securities, for the validity or worth of such securities, for any tax consequences that result from the ownership of ADSs, for the credit-worthiness of any third party, for allowing any rights to lapse under the terms of the deposit agreement, for the timeliness of any of our notices or for our failure to give notice.

• We and the Depositary will not be obligated to perform any act that is inconsistent with the terms of the deposit agreement.

• We and the Depositary disclaim any liability if we or the Depositary are prevented or forbidden from or subject to any civil or criminal penalty or restraint on account of, or delayed in, doing or performing any act or thing required by the terms of the deposit agreement, by reason of any provision, present or future of any law or regulation, or by reason of present or future provision of any provision of our Articles of Association, or any provision of or governing the securities on deposit, or by reason of any act of God or war or other circumstances beyond our control.

• We and the Depositary disclaim any liability by reason of any exercise of, or failure to exercise, any discretion provided for in the deposit agreement or in our Articles of Association or in any provisions of or governing the securities on deposit.

• We and the Depositary further disclaim any liability for any action or inaction in reliance on the advice or information received from legal counsel, accountants, any person presenting securities for deposit, any holder of ADSs or authorized representatives thereof, or any other person believed by either of us in good faith to be competent to give such advice or information.

• We and the Depositary also disclaim liability for the inability by a holder to benefit from any distribution, offering, right or other benefit that is made available to holders of ordinary shares but is not, under the terms of the deposit agreement, made available to you.

• We and the Depositary may rely without any liability upon any written notice, request or other document believed to be genuine and to have been signed or presented by the proper parties.

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• We and the Depositary also disclaim liability for any consequential or punitive damages for any breach of the terms of the deposit agreement.

• No disclaimer of any Securities Act liability is intended by any provision of the deposit agreement.

Pre-release transactions

Subject to the terms and conditions of the deposit agreement, the Depositary may issue ADSs before receiving a deposit of ordinary shares or release ordinary shares before receiving ADSs for cancellation. These transactions are commonly referred to as “pre-release transactions,” and are entered into between the Depositary and the applicable person. The deposit agreement limits the aggregate size of pre-release transactions (generally not to exceed 30% of the number of ADSs outstanding, which limit may be modified or disregarded in the Depositary’s discretion) and imposes a number of conditions on such transactions (i.e., the need to receive collateral, the type of collateral required, the representations required from persons entering into such transactions, etc.). The Depositary may retain the compensation received from the pre-release transactions.

Taxes

You will be responsible for the taxes and other governmental charges payable on the ADSs and the securities represented by the ADSs. We, the Depositary and the custodian may deduct from any distribution the taxes and governmental charges payable by holders and may sell any and all property on deposit to pay the taxes and governmental charges payable by holders. You will be liable for any deficiency if the sale proceeds do not cover the taxes that are due.

The Depositary may refuse to issue ADSs, to deliver, transfer, split and combine ADRs or to release securities on deposit until all taxes and charges are paid by the applicable holder. The Depositary and the custodian may take reasonable administrative actions to obtain tax refunds and reduced tax withholding for any distributions on your behalf. However, you may be required to provide to the Depositary and to the custodian proof of taxpayer status and residence and such other information as the Depositary and the custodian may require to fulfill legal obligations. You are required to indemnify us, the Depositary and the custodian for any claims with respect to taxes based on any tax benefit obtained for you.

Foreign currency conversion

The Depositary will arrange for the conversion of all foreign currency received into U.S. dollars if such conversion is practicable, and it will distribute the U.S. dollars in accordance with the terms of the deposit agreement. You may have to pay fees and expenses incurred in converting foreign currency, such as fees and expenses incurred in complying with currency exchange controls and other governmental requirements.

If the conversion of foreign currency is not practicable or lawful, or if any required approvals are denied or not obtainable at a reasonable cost or within a reasonable period, the Depositary may take the following actions in its discretion:

• Convert the foreign currency to the extent practicable and lawful and distribute the U.S. dollars to the holders for whom the conversion and distribution is lawful and practicable.

• Distribute the foreign currency to holders for whom the distribution is lawful and practicable.

• Hold the foreign currency (without liability for interest) for the applicable holders.

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Certain material U.K. tax considerations

The following discussion is limited to an overview of the tax consequences of ownership and disposition of ordinary shares, or such shares represented by ADSs. Tax considerations applicable to other types of securities will be described in the related prospectus supplement. Each shareholder should however seek individual tax advice as specific rules may apply in certain circumstances.

Capital gains

If you are not resident in the United Kingdom (“UK”) for UK tax purposes, you will not be liable for UK tax on capital gains realized or accrued on the sale or other disposition of shares or ADSs unless the shares or ADSs are held in connection with your trade carried on in the UK through a branch or agency and the ordinary shares or ADSs are or have been used, held or acquired for the purposes of such trade or such branch or agency.

An individual holder of shares or ADSs who ceases to be resident in the UK for UK tax purposes for a period of 5 years or less and who disposes of shares or ADSs during that period may also be liable on returning to the UK for UK capital gains tax despite the fact that the individual may not be resident in the UK at the time of the disposal.

Inheritance tax

If you are an individual domiciled in the United States and are not a national of the UK for the purposes of the Estate and Gift Tax Convention 1980 between the United States and the UK, any shares or ADS beneficially owned by you will not generally be subject to UK inheritance tax on your death or on a gift made by you during your lifetime, provided that any applicable United States federal gift or estate tax liability is paid, except where the share or ADS is part of the business property of your UK permanent establishment.

Where the ordinary shares or ADSs have been placed in trust by a settlor who, at the time of the settlement, was domiciled in the United States and not a national of the UK, the shares or ADSs will not generally be subject to UK inheritance tax.

Stamp duty and stamp duty reserve tax

Transfer of ADSs

No UK stamp duty will be payable on an instrument transferring an ADS or on a written agreement to transfer an ADS provided that the instrument of transfer or the agreement to transfer is executed and remains at all times outside the UK and there is nothing else to be done in the UK. Where these conditions are not met, the transfer of, or agreement to transfer, an ADS could, depending on the circumstances, attract a charge to ad valorem stamp duty at the rate of 0.5% of the value of the consideration.

No stamp duty reserve tax will be payable in respect of an agreement to transfer an ADS, whether made in or outside the UK.

Issue and transfer of shares

The issue of shares by Amarin will not give rise to a charge to UK stamp duty or stamp duty reserve tax under current UK and European Union law; it is not currently known whether this position will continue for UK stamp duty reserve tax in relation to the issue of shares in return for an issue of ADSs after the United Kingdom leaves the European Union. We would be responsible for any UK stamp duty reserve tax payable on the issue of shares in return for the issue of ADSs.

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Transfers of shares, as opposed to ADSs, will attract ad valorem stamp duty at the rate of 0.5% of the amount or value of the consideration. A charge to stamp duty reserve tax, at the rate of 0.5% of the amount or value of the consideration, will arise on an agreement to transfer ordinary shares. The stamp duty reserve tax is payable on the seventh day of the month following the month in which the charge arises. Where an instrument of transfer is executed and duly stamped before the expiry of a period of six years beginning with the date of that agreement, any stamp duty reserve tax that has not been paid ceases to be payable.

Taxation of dividends

Under UK law, there is no withholding tax on dividends paid on the shares or ADSs.

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Certain material Irish tax considerations

The summary only applies to U.S. Holders that legally and beneficially hold their ordinary shares, or such shares represented by ADSs evidenced by ADRs as capital assets (i.e. investments) and does not address special classes of holders including, but not limited to, dealers in securities, insurance companies, pension schemes, employee share ownership trusts, collective investment undertakings, charities, tax-exempt organizations, financial institutions and close companies, each of which may be subject to special rules not discussed below.

Solely for the purposes of this summary of Irish Tax Considerations, a “U.S. Holder” means a holder of shares or ADSs evidenced by ADRs that (i) beneficially owns the shares or ADSs registered in their name; (ii) is resident in the United States for the purposes of the Ireland-United States Double Taxation Convention, (the “Treaty”); (iii) in the case of an individual holder, is not also resident or ordinarily resident in Ireland for Irish tax purposes; (iv) in the case of a corporate holder, is not a resident in Ireland for Irish tax purposes and is not ultimately controlled by persons resident in Ireland; and (v) is not engaged in any trade or business and does not perform independent personal services through a permanent establishment or fixed base in Ireland; and (vi) is a qualified person as defined in Article 23 of the Treaty.

For Irish taxation purposes, and for the purposes of the Treaty, U.S. Holders of ADSs will be treated as the owners of the shares represented by such ADSs.

The following discussion is limited to the tax consequences of ownership and disposition of shares or ADSs. Tax considerations applicable to other types of securities will be described in the related prospectus supplement.

Taxation of dividends

We do not expect to pay dividends in the foreseeable future. Should we begin paying dividends, such dividends will generally be subject to dividend withholding tax, or DWT, in Ireland at the standard rate of income tax (currently 20%). Where DWT applies, we will be responsible for withholding such tax at source.

Dividends paid by us to U.S. Holders of shares or ADSs evidenced by ADRs will be exempt from DWT if, prior to the payment of such dividends, the recipient U.S. Holder delivers to us a declaration in the form prescribed by the Irish Revenue Commissioners. In addition, a certificate of residency in the form prescribed by the Irish Revenue Commissioners, will also be required if the US holder is an individual.

Where DWT is withheld from dividend payments to U.S. Holders of shares or ADSs evidenced by ADRs, such U.S. Holders can apply to the Irish Revenue Commissioners claiming a full refund of DWT paid by filing a declaration in the form prescribed by the Irish Revenue Commissioners. As above, a certificate of residency in the form prescribed by the Irish Revenue Commissioners, will also be required if the US holder is an individual.

The DWT rate applicable to U.S. Holders may be reduced under the terms of the Treaty, however, in the first instance, an exemption should be in place under Irish domestic legislation.

Irish source income

U.S. Holders will not be liable to Irish income tax on dividends paid by us.

Capital gains on disposals of shares or ADSs

U.S. Holders will not be subject to Irish capital gains tax, or CGT, on the disposal of shares or ADSs provided that such shares or ADSs are quoted on a stock exchange at the time of disposition such as NASDAQ. While it is our intention to continue the listing of ADSs on NASDAQ, no assurances can be given in this regard.

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If, for any reason, our ADSs cease to be listed on NASDAQ, U.S. Holders will not be subject to CGT on the disposal of their shares or ADSs provided that the shares or ADSs do not, at the time of the disposal, derive the greater part of their value from land, buildings, minerals, or mineral rights or exploration rights in Ireland.

Irish Capital Acquisitions Tax (CAT)

CAT comprises principally gift and inheritance tax. A gift or inheritance of shares or ADSs will come within the charge to CAT if either:

(i) the disponer or the donee/successor in relation to the gift or inheritance is resident or ordinarily resident in Ireland (please note that special rules with regard to residence apply where an individual is not domiciled in Ireland); or

(ii) the ordinary shares or ADSs are regarded as property situated in Ireland (e.g. shares would be regarded as Irish property if the share register is maintained in Ireland. ADSs, if registered, will be regarded as Irish property if the register is maintained in Ireland, or, if in bearer form, if the instrument of ownership is located in Ireland).

On the basis that the shares or ADSs (assuming they are registered) should not be regarded as property situated in Ireland (given that the registers are not maintained in Ireland), a gift or inheritance of the shares or ADSs should only come within the charge to Irish CAT if either the disponer or donee/successor is resident or ordinarily resident in Ireland at the date of the gift or inheritance.

The rate of CAT is currently 33% and is payable if the taxable value of the gift or inheritance exceeds certain tax-free thresholds. The appropriate tax-free threshold depends on the relationship between the disponer and the donee/successor. For example, in 2017 a child is entitled to a tax-free threshold of € 310,000 on a gift or inheritance from a parent, but all gifts and inheritances taken from disponers within the same group threshold since 5 December 1991 are taken into account when determining the level of the tax-free threshold available. A gift or inheritance received from a spouse is exempt from CAT.

The person who receives the gift or inheritance is generally accountable for any CAT due.

Irish stamp duty

No Irish stamp duty should arise on the transfer for cash of shares or ADSs on the basis that such a transfer does not relate to stocks or marketable securities of an Irish registered company. Ireland does not have any capital duty on the issue of shares.

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Use of proceeds

We will retain broad discretion over the use of the net proceeds from the sale of our securities offered by us under this prospectus. Except as described in any prospectus supplement, we currently anticipate using the net proceeds from the sale of our securities offered hereby primarily for general corporate purposes which include, but are not limited to, funding development and, if approved, the commercialization of our product candidates and to discover additional product candidates. We may also use a portion of the net proceeds to pay off outstanding indebtedness, if any, and/or acquire or invest in complementary businesses, products and technologies. Although we have no specific agreements, commitments or understandings with respect to any acquisition, we evaluate acquisition opportunities and engage in related discussions with other companies from time to time.

Pending the use of the net proceeds, we intend to invest the net proceeds in short-term, interest-bearing, investment-grade securities.

We will not receive any proceeds from the sale by selling security holders of the securities covered by this prospectus.

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Ratio of earnings to fixed charges

The following table sets forth our historical consolidated ratio of earnings to fixed charges for the periods shown. As of the date of this prospectus, we have no preference shares outstanding and we did not declare or pay any dividends on preference shares for the periods indicated. Therefore, the ratios of earnings to combined fixed charges and preference share dividends are the same as the ratios of earnings to fixed charges presented below.

	Year ended December 31,
	2012		2013		2014		2015		2016
Ratio of earnings to fixed charges (1)	$	—	$	—	$	—	$	—	$	—

(1) Earnings were not sufficient to cover fixed charges and approximately equal to the loss from continuing operations of $170.1 million, $169.4 million, $59.2 million, $118.2 million and $85.4 million for the years ended December 31, 2012, 2013, 2014, 2015 and 2016, respectively. For this reason, no ratios are provided for these periods.

Selling security holders

Information about selling security holders, where applicable, will be set forth in a prospectus supplement, in a post effective amendment, or in filings we make with the SEC which are incorporated into this prospectus by reference.

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Plan of distribution

We may sell the securities described in this prospectus in and outside the United States (a) through underwriters or dealers, (b) directly to purchasers, including our affiliates, (c) through agents or (d) through a combination of any of these methods. The applicable prospectus supplement or free writing prospectus will include the following information:

• the terms of the offering;

• the names of any underwriters or agents;

• the name or names of any managing underwriter or underwriters;

• the purchase price of the securities;

• the net proceeds from the sale of the securities;

• any delayed delivery arrangements;

• any underwriting discounts, commissions and other items constituting underwriters’ compensation;

• any initial public offering price;

• any discounts or concessions allowed or reallowed or paid to dealers; and

• any commissions paid to agents.

The sale of the securities may be effected in transactions (a) on any national or international securities exchange or quotation service on which the securities may be listed or quoted at the time of sale, (b) in the over-the-counter market, (c) in transactions otherwise than on such exchanges or in the over-the-counter market or (d) through the writing of options.

The distribution of offered securities may be effected from time to time in one or more transactions at a fixed price or prices, which may be changed, at market prices prevailing at the time of sale, at prices related to the market prices, or at negotiated prices.

Sale through underwriters or dealers

If underwriters are used in the sale of any of these securities, the underwriters will acquire the securities for their own account. The underwriters may resell the securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. Underwriters may offer securities to the public either through underwriting syndicates represented by one or more managing underwriters or directly by one or more firms acting as underwriters. Unless we inform you otherwise in any prospectus supplement or free writing prospectus, the obligations of the underwriters to purchase the securities will be subject to certain conditions, and the underwriters will be obligated to purchase all the offered securities if they purchase any of them. We may grant underwriters an option to purchase additional securities to cover overallotment, if any, or otherwise in connection with the distribution. The underwriters may change from time to time any initial public offering price and any discounts or concessions allowed or reallowed or paid to dealers.

Any underwriter may engage in overallotment, stabilizing transactions, short covering transactions and penalty bids in accordance with Regulation M under the Exchange Act. Overallotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum. Short covering transactions involve purchases of the securities in the open market after the distribution is completed to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of the activities at any time.

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Any underwriters who are qualified market makers on NASDAQ (or any exchange or quotation system on which our securities are listed) may engage in passive market making transactions in our ordinary shares, debt securities, warrants, ADSs or contracts, subscription rights or units, as applicable, on NASDAQ in accordance with Rule 103 of Regulation M, during the business day prior to the pricing of the offering, before the commencement of offers or sales of the securities. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded.

Some or all of the securities that we offer though this prospectus may be new issues of securities with no established trading market. Any underwriters to whom we sell these securities for public offering and sale may make a market in those securities, but they will not be obligated to and they may discontinue any market making at any time without notice. Accordingly, we cannot assure you of the liquidity of, or continued trading markets for, any securities that we offer.

If dealers are used in the sale of securities, we will sell the securities to them as principals. They may then resell those securities to the public at varying prices determined by the dealers at the time of resale. We will include in the prospectus supplement or free writing prospectus the names of the dealers and the terms of the transaction.

Direct sales and sales through agents

We may sell the securities directly, and not through underwriters or agents. We may also sell the securities through agents designated from time to time. In the prospectus supplement or free writing prospectus, we will name any agent involved in the offer or sale of the offered securities, and we will describe any commissions payable to the agent. Unless we inform you otherwise in the prospectus supplement or free writing prospectus, any agent will agree to use its reasonable best efforts to solicit purchases for the period of its appointment.

We may sell the securities directly to institutional investors or others who may be deemed to be underwriters within the meaning of the Securities Act with respect to any sale of those securities. We will describe the terms of any such sales in the prospectus supplement or free writing prospectus.

We may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement or free writing prospectus indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement or free writing prospectus, including in short sale transactions. If so, the third party may use securities pledged by us or borrowed from us or others to settle those sales or to close out any related open borrowings of stock, and may use securities received from us in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and, if not identified in this prospectus, will be identified in the applicable prospectus supplement or free writing prospectus (or a post-effective amendment).

Delayed delivery contracts

If we so indicate in the prospectus supplement or free writing prospectus, we may authorize agents, underwriters or dealers to solicit offers from certain types of institutions to purchase securities from us at the public offering price under delayed delivery contracts. These contracts would provide for payment and delivery on a specified date in the future. The contracts would be subject only to those conditions described in the prospectus supplement or free writing prospectus. The prospectus supplement or free writing prospectus will describe any commission payable for solicitation of those contracts.

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Subscription offerings

Direct sales to investors or our stockholders may be accomplished through subscription offerings or through subscription rights distributed to stockholders. In connection with subscription offerings or the distribution of subscription rights to stockholders, if all of the underlying securities are not subscribed for, we may sell any unsubscribed securities to third parties directly or through underwriters or agents. In addition, whether or not all of the underlying securities are subscribed for, we may concurrently offer additional securities to third parties directly or through underwriters or agents. If securities are to be sold through subscription rights, the subscription rights will be distributed as a dividend to the stockholders for which they will pay no separate consideration.

General information

We may have agreements with the agents, dealers and underwriters to indemnify them against certain civil liabilities, including liabilities under the Securities Act, or to contribute with respect to payments that the agents, dealers or underwriters may be required to make. Agents, dealers and underwriters may be customers of, engage in transactions with or perform services for us in the ordinary course of their businesses.

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Legal matters

Certain legal matters with respect to United States and New York law with respect to the validity of certain of the offered securities will be passed upon for the issuer by Goodwin Procter LLP, Boston, Massachusetts. Certain legal matters with respect to English law with respect to the validity of certain of the offered securities will be passed upon for the issuer by K&L Gates LLP (registered in England). Any underwriters will be advised about other issues relating to any offering by their own legal counsel.

Experts

The consolidated financial statements of Amarin Corporation plc appearing in Amarin Corporation plc’s Annual Report on Form 10-K for the year ended December 31, 2016, and the effectiveness of Amarin Corporation plc’s internal control over financial reporting as of December 31, 2016, have been audited by Ernst & Young LLP, independent registered public accounting firm, as set forth in their reports thereon, included therein, and incorporated herein by reference. Such consolidated financial statements are incorporated herein by reference in reliance upon such reports given on the authority of such firm as experts in accounting and auditing.

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Incorporation of certain information by reference

The SEC allows us to incorporate by reference into this prospectus the information contained in other documents we file with the SEC, which means that we can disclose important information to you by referring you to those documents. Any statement contained in any document incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or superseded, for purposes of this prospectus, to the extent that a statement contained in or omitted from this prospectus, or in any other subsequently filed document that also is or is deemed to be incorporated by reference herein, modifies or supersedes such statement. Any such statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute a part of this prospectus. We incorporate by reference the documents listed below which have been filed by us:

1. Our Annual Report on Form 10-K for the year ended December 31, 2016, filed with the SEC on March 1, 2017;

2. Our annual Proxy Statement on Schedule 14A relating to our annual meeting of stockholders, filed with the SEC on April 29, 2016 (with respect to those portions incorporated by reference into our Annual Report on Form 10-K for the year ended December 31, 2015);

3. Our Current Reports on Form 8-K filed with the SEC on January 20, 2017 and January 25, 2017; and

3. The section entitled “Description of Registrant’s Securities to be Registered” contained in the Registrant’s Registration Statement on Form 8-A filed with the Commission on March 19, 1993, including any amendment or report filed for the purpose of updating such description.

All documents we file with the SEC pursuant to Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act, except as to any portion of any report or documents that is not deemed filed under such provisions, (1) on or after the date of filing of the registration statement containing this prospectus and prior to the effectiveness of the registration statement and (2) on or after the date of this prospectus until the earlier of the date on which all of the securities registered hereunder have been sold or the registration statement of which this prospectus is a part has been withdrawn, shall be deemed incorporated by reference in this prospectus and to be a part of this prospectus from the date of filing of those documents.

We will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus is delivered, upon such person’s written or oral request, a copy of any and all of the information incorporated by reference in this prospectus, other than exhibits to such documents, unless such exhibits are specifically incorporated by reference into the information that this prospectus incorporates. Requests should be directed to Investor Relations of Amarin Corporation plc, c/o Amarin Pharma, Inc., 1430 Route 206, Bedminster, New Jersey 07921; telephone: (908) 719-1315. We have not authorized anyone to provide you with any information that differs from that contained in this prospectus. Accordingly, you should not rely on any information that is not contained in this prospectus. You should not assume that the information in this prospectus is accurate as of any date other than the date of the front cover of this prospectus.

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Where you can find more information

We have filed a registration statement, of which this prospectus is a part, covering the securities offered hereby. As allowed by SEC rules, this prospectus does not include all of the information contained in the registration statement. You are referred to the registration statement and the included exhibits for further information. This prospectus is qualified in its entirety by such other information.

We are subject to the informational requirements of the Securities Exchange Act and file annual, quarterly and current reports, proxy statements and other information with the SEC. You can read our SEC filings, including the registration statement, over the Internet at the SEC’s website at www.sec.gov. You may also read and copy any document we file with the SEC at its Public Reference Room at 100 F Street, N.E., Washington, D.C., 20549. Please call the SEC at 1-800-SEC-0330 for further information on the operation of the public reference facility. Additionally, we make these filings available, free of charge, on our website at www.amarincorp.com as soon as reasonably practicable after we electronically file such materials with, or furnish them to, the SEC.

*    *    *

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22,222,223

American Depositary Shares

Representing 22,222,223 Ordinary Shares

Prospectus supplement

Joint Book-Running Managers

J.P. Morgan

Goldman Sachs & Co. LLC

Jefferies

Cantor

Co-Managers

H.C. Wainwright & Co.

Roth Capital Partners

July 18, 2019