Nature of Business and Basis of Presentation	12 Months Ended
Dec. 31, 2021
Accounting Policies [Abstract]
Nature of Business and Basis of Presentation	(1) Nature of Business and Basis of Presentation Nature of Business Amarin Corporation plc, or Amarin, or the Company, is a pharmaceutical company focused on the commercialization and development of therapeutics to improve cardiovascular, or CV, health and reduce CV risk. Most of the Company’s historical revenue and sales, marketing and administrative activities and costs have been associated with commercial operations in the United States, or U.S. In 2021 the Company began to increase pre-launch commercial activities throughout Europe. As of September 1, 2021, product was made available in Germany and as of October 1, 2021 was included in the country's electronic prescribing system. The Company’s operations outside of the U.S. and Europe are in early stages of development with reliance on third-party commercial partners in select geographies, including China where regulatory approval for the Company’s lead product is being actively sought. The Company’s lead product, VASCEPA® (icosapent ethyl), was first approved by the U.S. Food and Drug Administration, or U.S. FDA, in July 2012 for use as an adjunct to diet to reduce triglyceride, or TG, levels in adult patients with severe (>500 mg/dL) hypertriglyceridemia. In January 2013, the Company launched 1-gram size VASCEPA in the U.S. and in October 2016, introduced a smaller 0.5-gram capsule size. On December 13, 2019, the U.S. FDA approved another indication and label expansion for VASCEPA based on the results of the Company’s long-term cardiovascular outcomes trial, REDUCE-IT®, or Reduction of Cardiovascular Events with EPA – Intervention Trial. VASCEPA is approved by the U.S. FDA as an adjunct to maximally tolerated statin therapy for reducing persistent cardiovascular risk in select high risk patients. On March 30, 2020, following conclusion of a trial in late January 2020, the U.S. District Court for the District of Nevada, or the Nevada Court, issued a ruling in favor of two generic drug companies, Dr. Reddy's Laboratories, Inc., or Dr. Reddy's, and Hikma Pharmaceuticals USA Inc., or Hikma, and certain of their affiliates, or collectively, the Defendants, that declared as invalid several of the Company's patents covering the first U.S. FDA-approved use of its drug, for use to reduce severely high triglyceride levels, which is known as the MARINE indication. The Company sought appeals of the Nevada Court judgment up to the United States Supreme Court, but the Company was unsuccessful. Most recently, on June 18, 2021, the Company was notified that its petition for writ of certiorari to the United States Supreme Court was denied. On May 22, 2020, Hikma received U.S. FDA approval to market its generic version of VASCEPA for the MARINE indication of VASCEPA. In November 2020, Hikma launched their generic version of VASCEPA on a limited scale. On November 30, 2020 the Company filed a patent infringement lawsuit against Hikma for making, selling, offering to sell and importing generic icosapent ethyl capsules in and into the United States in a manner that the Company alleges has induced the infringement of patents covering the use of VASCEPA to reduce specified cardiovascular risk. On January 4, 2022, the district court hearing the case granted Hikma's motion to dismiss. Amarin intends to appeal the decision of the district court. Amarin also intends to continue to vigorously pursue the ongoing litigation with Health Net, LLC, but cannot predict the outcome or impact on its business. On August 10, 2020, Dr. Reddy’s received U.S. FDA approval to market its generic version for the MARINE indication of VASCEPA. In June 2021, Dr. Reddy's launched its generic version of VASCEPA with labeling that is substantially similar to labeling of the Hikma generic product. On September 11, 2020, Teva Pharmaceuticals USA, Inc.'s, or Teva's, abbreviated new drug application, or ANDA, was approved by the U.S. FDA and on June 30, 2021, Apotex, Inc.'s, or Apotex's, ANDA was approved by the U.S. FDA. In January 2022, Apotex launched its generic version of VASCEPA with labeling that is substantially consistent with the labeling of the Hikma and Dr. Reddy's generic product, not the cardiovascular risk reduction indication. On March 26, 2021, the European Commission, or EC, approved the marketing authorization application for VAZKEPA, hereinafter along with the U.S. brand name VASCEPA, collectively referred to as VASCEPA, in the EU to reduce the risk of cardiovascular events in high-risk, statin-treated adult patients who have elevated triglycerides (>150 mg/dL) and either established cardiovascular disease or diabetes and at least one additional cardiovascular risk event. On September 13, 2021, the Company launched VAZKEPA in Germany, representing the Company's first European launch. On April 22, 2021, the Company announced that the Medicines and Healthcare Products Regulatory Agency, or MHRA, approved VAZKEPA in England, Scotland and Wales to reduce cardiovascular risk through MHRA’s new ‘reliance’ route following the end of the BREXIT transition period. Collectively CHMP, EMA, EC and MHRA are referred to herein as the European Regulatory Authorities. In November 2020, the Company announced topline results from the Phase 3 clinical trial of VASCEPA conducted by the Company’s partner in China. On February 9, 2021, the Company announced that regulatory review processes for approval of VASCEPA in Mainland China and Hong Kong have commenced. The Chinese National Medical Products Administration, or NMPA, has accepted for review the new drug application for VASCEPA based on the results from the Phase 3 clinical trial and the results from the Company’s prior studies of VASCEPA. The Hong Kong Department of Health is evaluating VASCEPA based on current approvals in the United States and Canada. The Company currently has strategic collaborations to develop and commercialize VASCEPA in select territories outside the United States. Amarin is responsible for supplying VASCEPA to all markets in which the product is sold, including the United States and Germany, as well as, in Canada, Lebanon and the United Arab Emirates where the drug is promoted and sold via collaboration with third-party companies that compensate Amarin for such supply. Amarin is not responsible for providing any generic company with drug product. The Company operates in one business segment. Basis of Presentation The consolidated financial statements included herein have been prepared by the Company in accordance with accounting principles generally accepted in the United States and pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC. The consolidated financial statements reflect all adjustments of a normal and recurring nature that, in the opinion of management, are necessary to present fairly the Company’s financial position, results of operations and cash flows for the periods indicated. The preparation of the Company’s consolidated financial statements in conformity with U.S. Generally Accepted Accounting Principles, or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. The results of operations for the years ended December 31, 2021, 2020 and 2019 are not necessarily indicative of the results for any future period. Certain numbers presented throughout this document may not add precisely to the totals provided due to rounding. Absolute and percentage changes are calculated using the underlying amounts in thousands. The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation. The accompanying consolidated financial statements of the Company and subsidiaries have been prepared on a basis which assumes that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business, as well as the ongoing global pandemic, COVID-19. At December 31, 2021, the Company had Total assets of $1,068.1 million, of which $489.1 million consisted of cash and liquid short-term and long-term investments. More specifically, the Company had Current assets of $878.7 million, including Cash and cash equivalents of $219.5 million, Short-term investments of $234.7 million, Accounts receivable, net, of $163.7 million and Inventory of $234.7 million. In addition, at December 31, 2021, the Company had Long-term investments of $35.0 million and Long-term inventory of $121.3 million. At December 31, 2021, the Company had no debt outstanding.

Nature of Business and Basis of Presentation

12 Months Ended

Dec. 31, 2021

Nature of Business and Basis of Presentation

(1)

Nature of Business and Basis of Presentation

Nature of Business

Amarin Corporation plc, or Amarin, or the Company, is a pharmaceutical company focused on the commercialization and development of therapeutics to improve cardiovascular, or CV, health and reduce CV risk. Most of the Company’s historical revenue and sales, marketing and administrative activities and costs have been associated with commercial operations in the United States, or U.S. In 2021 the Company began to increase pre-launch commercial activities throughout Europe. As of September 1, 2021, product was made available in Germany and as of October 1, 2021 was included in the country's electronic prescribing system. The Company’s operations outside of the U.S. and Europe are in early stages of development with reliance on third-party commercial partners in select geographies, including China where regulatory approval for the Company’s lead product is being actively sought.

The Company’s lead product, VASCEPA® (icosapent ethyl), was first approved by the U.S. Food and Drug Administration, or U.S. FDA, in July 2012 for use as an adjunct to diet to reduce triglyceride, or TG, levels in adult patients with severe (>500 mg/dL) hypertriglyceridemia. In January 2013, the Company launched 1-gram size VASCEPA in the U.S. and in October 2016, introduced a smaller 0.5-gram capsule size. On December 13, 2019, the U.S. FDA approved another indication and label expansion for VASCEPA based on the results of the Company’s long-term cardiovascular outcomes trial, REDUCE-IT®, or Reduction of Cardiovascular Events with EPA – Intervention Trial. VASCEPA is approved by the U.S. FDA as an adjunct to maximally tolerated statin therapy for reducing persistent cardiovascular risk in select high risk patients.

On March 30, 2020, following conclusion of a trial in late January 2020, the U.S. District Court for the District of Nevada, or the Nevada Court, issued a ruling in favor of two generic drug companies, Dr. Reddy's Laboratories, Inc., or Dr. Reddy's, and Hikma Pharmaceuticals USA Inc., or Hikma, and certain of their affiliates, or collectively, the Defendants, that declared as invalid several of the Company's patents covering the first U.S. FDA-approved use of its drug, for use to reduce severely high triglyceride levels, which is known as the MARINE indication. The Company sought appeals of the Nevada Court judgment up to the United States Supreme Court, but the Company was unsuccessful. Most recently, on June 18, 2021, the Company was notified that its petition for writ of certiorari to the United States Supreme Court was denied.

On May 22, 2020, Hikma received U.S. FDA approval to market its generic version of VASCEPA for the MARINE indication of VASCEPA. In November 2020, Hikma launched their generic version of VASCEPA on a limited scale. On November 30, 2020 the Company filed a patent infringement lawsuit against Hikma for making, selling, offering to sell and importing generic icosapent ethyl capsules in and into the United States in a manner that the Company alleges has induced the infringement of patents covering the use of VASCEPA to reduce specified cardiovascular risk. On January 4, 2022, the district court hearing the case granted Hikma's motion to dismiss. Amarin intends to appeal the decision of the district court. Amarin also intends to continue to vigorously pursue the ongoing litigation with Health Net, LLC, but cannot predict the outcome or impact on its business. On August 10, 2020, Dr. Reddy’s received U.S. FDA approval to market its generic version for the MARINE indication of VASCEPA. In June 2021, Dr. Reddy's launched its generic version of VASCEPA with labeling that is substantially similar to labeling of the Hikma generic product. On September 11, 2020, Teva Pharmaceuticals USA, Inc.'s, or Teva's, abbreviated new drug application, or ANDA, was approved by the U.S. FDA and on June 30, 2021, Apotex, Inc.'s, or Apotex's, ANDA was approved by the U.S. FDA. In January 2022, Apotex launched its generic version of VASCEPA with labeling that is substantially consistent with the labeling of the Hikma and Dr. Reddy's generic product, not the cardiovascular risk reduction indication.

On March 26, 2021, the European Commission, or EC, approved the marketing authorization application for VAZKEPA, hereinafter along with the U.S. brand name VASCEPA, collectively referred to as VASCEPA, in the EU to reduce the risk of cardiovascular events in high-risk, statin-treated adult patients who have elevated triglycerides (>150 mg/dL) and either established cardiovascular disease or diabetes and at least one additional cardiovascular risk event. On September 13, 2021, the Company launched VAZKEPA in Germany, representing the Company's first European launch. On April 22, 2021, the Company announced that the Medicines and Healthcare Products Regulatory Agency, or MHRA, approved VAZKEPA in England, Scotland and Wales to reduce cardiovascular risk through MHRA’s new ‘reliance’ route following the end of the BREXIT transition period. Collectively CHMP, EMA, EC and MHRA are referred to herein as the European Regulatory Authorities.

In November 2020, the Company announced topline results from the Phase 3 clinical trial of VASCEPA conducted by the Company’s partner in China. On February 9, 2021, the Company announced that regulatory review processes for approval of VASCEPA in Mainland China and Hong Kong have commenced. The Chinese National Medical Products Administration, or NMPA, has accepted for review the new drug application for VASCEPA based on the results from the Phase 3 clinical trial and the results from the Company’s prior studies of VASCEPA. The Hong Kong Department of Health is evaluating VASCEPA based on current approvals in the United States and Canada.

The Company currently has strategic collaborations to develop and commercialize VASCEPA in select territories outside the United States. Amarin is responsible for supplying VASCEPA to all markets in which the product is sold, including the United States and Germany, as well as, in Canada, Lebanon and the United Arab Emirates where the drug is promoted and sold via collaboration with third-party companies that compensate Amarin for such supply. Amarin is not responsible for providing any generic company with drug product. The Company operates in one business segment.

Basis of Presentation

The consolidated financial statements included herein have been prepared by the Company in accordance with accounting principles generally accepted in the United States and pursuant to the rules and regulations of the Securities and Exchange Commission, or the SEC.

The consolidated financial statements reflect all adjustments of a normal and recurring nature that, in the opinion of management, are necessary to present fairly the Company’s financial position, results of operations and cash flows for the periods indicated. The preparation of the Company’s consolidated financial statements in conformity with U.S. Generally Accepted Accounting Principles, or GAAP, requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities, disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. The results of operations for the years ended December 31, 2021, 2020 and 2019 are not necessarily indicative of the results for any future period. Certain numbers presented throughout this document may not add precisely to the totals provided due to rounding. Absolute and percentage changes are calculated using the underlying amounts in thousands. The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.

The accompanying consolidated financial statements of the Company and subsidiaries have been prepared on a basis which assumes that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities and commitments in the normal course of business, as well as the ongoing global pandemic, COVID-19.

At December 31, 2021, the Company had Total assets of $1,068.1 million, of which $489.1 million consisted of cash and liquid short-term and long-term investments. More specifically, the Company had Current assets of $878.7 million, including Cash and cash equivalents of $219.5 million, Short-term investments of $234.7 million, Accounts receivable, net, of $163.7 million and Inventory of $234.7 million. In addition, at December 31, 2021, the Company had Long-term investments of $35.0 million and Long-term inventory of $121.3 million. At December 31, 2021, the Company had no debt outstanding.