8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): April 24, 2012

HUMAN GENOME SCIENCES, INC.

(Exact name of registrant as specified in its charter)

Delaware	001-14169	22-3178468
(State or other Jurisdiction of Incorporation)	(Commission File Number)	(IRS Employer Identification No.)

14200 Shady Grove Road, Rockville, Maryland	20850-7464
(Address of Principal Executive Offices)	(Zip Code)

Registrant’s telephone number, including area code: (301) 309-8504

(Former name or former address if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Section 2 — Financial Information

Item 2.02. Results of Operations and Financial Condition.

On April 24, 2012, Human Genome Sciences, Inc. issued a press release announcing its financial results for the quarter ended March 31, 2012. A copy of the release is furnished as Exhibit 99.1 to this Current Report on Form 8-K. The slide presentation that will be used by management during the conference call to discuss the financial results for the quarter ended March 31, 2012 is furnished as Exhibit 99.2 to this Current Report on Form 8-K.

Section 9 — Financial Statements and Exhibits

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits.

99.1	Press Release, dated April 24, 2012.
99.2	Slide Presentation relating to earnings conference call.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

HUMAN GENOME SCIENCES, INC.
By:	/s/ JAMES H. DAVIS, PH.D.
Name:	James H. Davis, Ph.D.
Title:	Executive Vice President, General Counsel and Secretary

Date: April 24, 2012

INDEX TO EXHIBITS

Exhibit No.	Description
99.1	Press Release, dated April 24, 2012.
99.2	Slide Presentation relating to earnings conference call.

EX-99.1

Exhibit 99.1

Media Contacts:	Investor Contact:
Susannah Budington	Claudine Prowse, Ph.D.
Director, Corporate Public Relations	Vice President, Investor Relations
301-545-1062	301-610-5800

Jerry Parrott

Vice President, Corporate Communications

301-315-2777

HUMAN GENOME SCIENCES ANNOUNCES FIRST QUARTER 2012 FINANCIAL RESULTS

ROCKVILLE, Maryland – April 24, 2012 – Human Genome Sciences, Inc. (Nasdaq: HGSI) today announced financial results for the quarter ended March 31, 2012, and provided recent highlights.

“We continue to see quarter-to-quarter progress in BENLYSTA sales,” said H. Thomas Watkins, President and Chief Executive Officer. “A growing body of evidence from our market research indicates that BENLYSTA is making a difference for patients with systemic lupus – and that rheumatologists who have the most experience with BENLYSTA are the ones who are most impressed with its efficacy. As lupus-treating physicians gain experience with BENLYSTA, we believe their use of BENLYSTA will expand to greater numbers of patients.”

FINANCIAL RESULTS

HGS reported revenues for the quarter ended March 31, 2012 of $47.1 million, compared with revenues of $26.6 million for the same period in 2011. Revenues included $31.2 million recognized from sales of BENLYSTA, $6.1 million recognized from sales and deliveries of raxibacumab to the U.S. Strategic National Stockpile and $9.1 million recognized from manufacturing and development services other than raxibacumab.

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The Company reported a net loss of $93.5 million ($0.47 per share) for the first quarter of 2012, compared with a net loss of $131.0 million ($0.69 per share) for the first quarter of 2011. The decreased net loss for the current quarter, compared with the same quarter last year, is primarily due to revenue from BENLYSTA sales and decreased research and development expenses, partially offset by increased commercial collaboration expenses related to BENLYSTA.

As of March 31, 2012, cash and investments totaled $798.7 million, of which $719.2 million was unrestricted and available for operations. This compares with cash and investments totaling $881.4 million as of December 31, 2011, of which $801.2 million was unrestricted and available for operations.

“HGS continues to have a strong financial position,” said David P. Southwell, Executive Vice President and Chief Financial Officer. “BENLYSTA will continue to be our company’s most important driver of growth for the next several years. Supporting its worldwide commercial progress and further development remain our most important financial priority.”

HIGHLIGHTS OF RECENT PROGRESS

BENLYSTA Sales Continue to Progress

BENLYSTA gross sales for the first quarter of 2012 totaled $35.6 million. After gross-to-net adjustments of $4.4 million, net sales of BENLYSTA for the quarter totaled $31.2 million, compared with $25.7 million in the quarter ended December 31, 2011. During the first quarter, BENLYSTA average weekly gross sales for the last four weeks of March were $2.94 million, compared with $2.76 million and $2.52 million for the preceding four-week periods, respectively.

The number of accounts ordering BENLYSTA continues to increase. HGS sales data suggest that more than 50% of key accounts have initiated treatment of at least one patient with BENLYSTA as of the end of March 2012. Among the community-based accounts that are the largest infusing practices, approximately 80% have begun to purchase BENLYSTA. Among the top 50 key hospital accounts, more than 80% have begun to purchase BENLYSTA.

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Raxibacumab: Deliveries to U.S. Strategic National Stockpile Continued Under Second BARDA Order

In July 2009, the U.S. Government exercised its option to purchase 45,000 additional doses of raxibacumab for the U.S. Strategic National Stockpile for emergency use in treating inhalation anthrax, with delivery to be completed over a three-year period. HGS expects to receive approximately $142 million from this second award as deliveries are completed, including approximately $123 million received through March 31, 2012. Raxibacumab is being developed under a contract entered into in 2006 with the Biomedical Advanced Research and Development Authority (BARDA) of the Office of the Assistant Secretary for Preparedness and Response (ASPR), U.S. Department of Health and Human Services (HHS).

Darapladib: Two Global Phase 3 Trials Ongoing in More than 28,000 Patients

GSK’s Phase 3 program for darapladib continues to progress. Darapladib is the first in a new class of drugs that directly inhibits the biological activity of an enzyme known as lipoprotein-associated phospholipase A2 (Lp-PLA2). Two pivotal Phase 3 trials are evaluating whether darapladib can reduce the risk of adverse cardiovascular events such as heart attack or stroke in patients with chronic coronary heart disease (CHD) and acute coronary syndrome (ACS). GSK has completed the enrollment of over 13,000 patients into the study in patients who have suffered an ACS event. The other study is evaluating darapladib in about 15,800 patients with CHD. Darapladib was discovered by GSK based on HGS technology. HGS will receive 10% royalties on worldwide sales if darapladib is commercialized, and has a 20% co-promotion option in North America and Europe.

Albiglutide: GSK Announces Further Data from Phase 3 Trials

GlaxoSmithKline (GSK) announced on April 3, 2012, that it has reviewed primary endpoint data from seven of eight Phase 3 studies designed to evaluate the efficacy and safety of albiglutide, versus placebo and active controls, in type 2 diabetes. GSK said that the data reviewed to date support progression to regulatory submissions of albiglutide as a possible once-weekly treatment for this disease.

Albiglutide was created by HGS using its proprietary albumin-fusion technology, and was licensed to GSK in 2004. HGS is entitled to fees and milestone payments that could amount to as much as $183 million – including $33.0 million received to date – in addition to single-digit net royalties on worldwide sales if albiglutide is commercialized.

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Mapatumumab: Randomized Phase 2 Combination Trial Fully Enrolled

In March 2012, HGS completed the enrollment and initial dosing of 101 patients ahead of schedule in a randomized Phase 2 trial of mapatumumab with Nexavar (sorafenib) in hepatocellular cancer.

CONFERENCE CALL

HGS management will hold a conference call to discuss this announcement today at 4:30 PM Eastern. Investors may listen to the call by dialing 888-312-9844 or 719-325-2111, passcode 3946943. A replay of the conference call will be available within a few hours after the call ends. Investors may listen to the replay by dialing 888-203-1112 or 719-457-0820, confirmation code 3946943. Today’s conference call also will be webcast and can be accessed at www.hgsi.com. It is recommended that investors interested in listening to the live webcast log on before the start of the call to download any software required. Both the audio replay and the archive of the conference call webcast will remain available for several days.

ABOUT HUMAN GENOME SCIENCES

Human Genome Sciences exists to place new therapies into the hands of those battling serious disease.

For more information about HGS, please visit the Company’s web site at www.hgsi.com. Health professionals and patients interested in clinical trials of HGS products may inquire via email to clinicaltrialsinfo@hgsi.com or by calling HGS at 1-240-314-4430.

HGS, Human Genome Sciences and BENLYSTA are trademarks of Human Genome Sciences, Inc. Other trademarks referenced are the property of their respective owners.

SAFE HARBOR STATEMENT

This announcement includes statements that are forward-looking within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include those regarding our expectations for BENLYSTA, raxibacumab, darapladib albiglutide and mapatumumab, among others. These forward-looking statements are based on our current intentions, beliefs and expectations regarding future events. We cannot guarantee that any forward-looking statement will be accurate. Investors should realize that if underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results could differ materially from our expectations. Investors are, therefore, cautioned not to place undue reliance on any forward-looking statement. Any forward-looking statement speaks only as of the date of this announcement, and, except as required by law, we do not undertake to update any forward-looking statement to reflect new information, events or circumstances.

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Some important factors that could cause our actual results to differ from our expectations in these forward-looking statements include: our lack of commercial experience and dependence on the sales growth of BENLYSTA; any failure to commercialize BENLYSTA successfully; the occurrence of adverse safety events with our products; changes in the availability of reimbursement for BENLYSTA; the inherent uncertainty of the timing, success of, and expense associated with, research, development, regulatory approval and commercialization of our pipeline products, including darapladib and new indications for existing products; substantial competition in our industry, including from branded and generic products; the highly regulated nature of our business; uncertainty regarding our intellectual property rights and those of others; the ability to manufacture at appropriate scale, and in compliance with regulatory requirements, to meet market demand for our products; our substantial indebtedness and lease obligations; our dependence on collaborations over which we may not always have full control; foreign exchange rate valuations and fluctuations; the impact of our acquisitions and strategic transactions; changes in the health care industry in the U.S. and other countries, including government laws and regulations relating to sales and promotion, reimbursement and pricing generally; significant litigation adverse to the Company, including product liability and patent infringement claims; our ability to attract and retain key personnel; and increased scrutiny of the health care industry by government agencies and state attorneys general resulting in investigations and prosecutions.

The foregoing list sets forth many, but not all, of the factors that could cause actual results to differ from our expectations in any forward-looking statement. Investors should consider this cautionary statement, as well as the risk factors identified in our periodic reports filed with the SEC, when evaluating our forward-looking statements.

.

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HUMAN GENOME SCIENCES, INC.

CONSOLIDATED STATEMENTS OF OPERATIONS

	Three months ended March 31,
	2012			2011
	(in thousands, except share and per share amounts)
Revenue:
Product sales	$	37,376		$	14,110
Manufacturing and development services		9,507			12,264
Research and development collaborative agreements		245			199
Total revenue		47,128			26,573
Costs and expenses:
Cost of product sales		8,279			9,999
Cost of manufacturing and development services		19,500			11,599
Research and development expenses		39,569			84,485
Selling, general and administrative expenses		40,287			35,120
Commercial collaboration expenses		15,677			3,086
Facility-related exit credits		—			(1,717	)
Total costs and expenses (a)		123,312			142,572
Income (loss) from operations		(76,184	)		(115,999	)
Investment income		1,999			3,252
Interest expense		(19,378	)		(15,276	)
Other income (expense)		68			(2,972	)
Income (loss) before taxes		(93,495	)		(130,995	)
Provision for income taxes		—			—
Net income (loss)	$	(93,495	)	$	(130,995	)
Basic and diluted net income (loss) per share	$	(0.47	)	$	(0.69	)
Weighted average shares outstanding,basic and diluted		198,972,188			189,076,628

(a) Includes stock-based compensation expense of $10,790 ($0.05 per basic and diluted share) and $6,612 ($0.03 per basic and diluted share) for the three months ended March 31, 2012 and 2011, respectively.

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CONSOLIDATED BALANCE SHEET DATA:

	As of		As of
	March 31, 2012		December 31, 2011
	(in thousands)
Cash, cash equivalents and investments (b) $		798,680	$	881,434
Total assets (b)		1,328,170		1,407,576
Convertible debt (c)		569,028		561,735
Lease financing		252,476		252,105
Total stockholders’ equity		376,672		456,419

(b) Includes $79,493 and $80,193 in restricted investments as of March 31, 2012 and December 31, 2011, respectively.

(c) Convertible senior debt at face value is $494,500 (book value $367,330) and convertible subordinated debt at face value is $206,736 (book value $201,698) as of March 31, 2012. Convertible senior debt at face value is $494,500 (book value $363,698) and convertible subordinated debt at face value is $206,736 (book value $198,037) as of December 31, 2011.

# # #

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EX-99.2

Exhibit 99.2

CONFERENCE CALL & WEBCAST April 24, 2012

2 NOTE REGARDING FORWARD-LOOKING STATEMENTS This presentation includes statements that are forward-looking within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include those regarding our expectations for BENLYSTA(r), darapladib, and other assets, business goals for 2012, and our financial guidance. These forward-looking statements are based on our current intentions, beliefs and expectations regarding future events. We cannot guarantee that any forward-looking statement will be accurate. Investors should realize that if underlying assumptions prove inaccurate or unknown risks or uncertainties materialize, actual results could differ materially from our expectations. Investors are, therefore, cautioned not to place undue reliance on any forward-looking statement. Any forward-looking statement speaks only as of the date of this presentation, and, except as required by law, we do not undertake to update any forward- looking statement to reflect new information, events or circumstances. Some important factors that could cause our actual results to differ from our expectations in these forward-looking statements include: our lack of commercial experience and dependence on the sales growth of BENLYSTA; any failure to commercialize BENLYSTA successfully; the occurrence of adverse safety events with our products; changes in the availability of reimbursement for BENLYSTA; the inherent uncertainty of the timing, success of, and expense associated with, research, development, regulatory approval and commercialization of pipeline products, including darapladib, and new indications for existing products; substantial competition in our industry, including from branded and generic products; the highly regulated nature of our business; uncertainty regarding our intellectual property rights and those of others; the ability to manufacture at appropriate scale, and in compliance with regulatory requirements, to meet market demand for our products; our substantial indebtedness and lease obligations; our dependence on collaborations over which we may not always have full control; foreign exchange rate valuations and fluctuations; the impact of our acquisitions and strategic transactions; changes in the health care industry in the U.S. and other countries, including government laws and regulations relating to sales and promotion, reimbursement and pricing generally; significant litigation adverse to the company, including product liability and patent infringement claims; our ability to attract and retain key personnel; and increased scrutiny of the health care industry by government agencies and state attorneys general resulting in investigations and prosecutions. The foregoing list sets forth many, but not all, of the factors that could cause actual results to differ from our expectations in any forward- looking statement. Investors should consider this cautionary statement, as well as the risk factors identified in our periodic reports filed with the SEC, when evaluating our forward-looking statements HGS, Human Genome Sciences, and BENLYSTA are trademarks of Human Genome Sciences, Inc. Other trademarks referenced are the property of their respective owners.

We remain confident in the future potential of HGS and our Board is committed to maximizing shareholder value BENLYSTA - a blockbuster in progress BENLYSTA is the first drug in >50 years to be approved for the treatment of Lupus Lupus is a complicated disease with a unique treatment approach - physicians "try, observe, then adopt" Our market research indicates that most physicians are now "trying" BENLYSTA; real world efficacy is favorable, therefore we expect adoption rates to increase more rapidly The U.S. market represents a $7+ billion opportunity We have equal operational rights and share 50% of worldwide profits with GSK Darapladib - a blockbuster in the making Novel treatment for 30+ million cardiovascular disease patients We retain a 10% worldwide sales royalty AND 20% co-promotion / profit share option (in North America and Europe) Upon a change of control, our financial and commercial rights to all programs are fully transferable Pipeline represents a significant upside opportunity for shareholders Balance sheet is strong - $799 million cash and $701 million debt $2.4 billion in NOLs Unsolicited GSK proposal does not reflect the inherent value of the company EXECUTIVE SUMMARY 3

Clinical and Regulatory Success: The only treatment to complete randomized placebo-controlled Phase 3 trials successfully in patients with SLE A broad label reflecting success in the clinic1 Strong Market Demand: 90%+ intent-to-use BENLYSTA among rheumatologists Estimated initial U.S. market of ~200,000 patients Significant opportunity outside the U.S. Additional Drivers of Growth Beyond Entry in SLE: Significant investment underway Subcutaneous formulation may enable weekly self-administration (initiated in Q4 2011) Phase III trials for new indications, vasculitis and lupus nephritis (initiation expected in 2H 2012) Exploratory / proof-of concept studies in many other diseases and syndromes Strong intellectual property rights and limited near term competition: Patent protection through 2025 BENLYSTA(r): THE FIRST DRUG IN 50 YEARS TO TREAT LUPUS 4 1BENLYSTA is indicated in the U.S. for the treatment of adult patients with active, autoantibody- positive, systemic lupus erythematosus who are receiving standard therapy. Limitations of Use: The efficacy of BENLYSTA has not been evaluated in patients with severe active lupus nephritis or severe active central nervous system lupus. BENLYSTA has not been studied in combination with other biologics or intravenous cyclophosphamide. Use of BENLYSTA is not recommended in these situations.

SLE IS A UNIQUE AND COMPLICATED DISEASE, WHICH IMPACTS THE RATE OF NEW TREATMENT ADOPTION 5 A chronic, life-threatening autoimmune disease, complicated by the following: Often affects multiple organ systems simultaneously (skin, joint and immunologic most common) Broad set of symptoms, including severe pain, extreme fatigue, swollen joints, skin rash and kidney problems Symptoms wax and wane Mortality rate 2-5x normal Eyes and Mucous Membranes Heart and Lungs Skin Gastrointestinal System Reproductive System Musculoskeletal System Joints Kidneys Central Nervous System Blood Due to the complexity of the disease, physicians often take time to identify patients that would benefit from treatment

6 ADOPTION BY PHYSICIANS IS ACCELERATING Waiters ...with Increasing Rate of Adoption in 1Q12 vs. 4Q11 Physicians try BENLYSTA on select patients, then observe clinical outcomes before adopting more broadly Accounts with > $15k Rolling 4-Week Average (~5+ patients) Physicians are Increasingly Trying BENLYSTA... Percentage of Accounts Generating Sales 1 1-2 month lag between physician prescribing and infusing of BENLYSTA patients. 76% of physicians report prescribing BENLYSTA (leading indicator)1 Physicians wait for further information on BENLYSTA; physicians are not prescribing Physicians select 1-3 patients to "trial" BENLYSTA; observation period typically lasts for up to 6-9 months "Trial" patients experience some benefit after at least 3 months Physicians begin to prescribe BENLYSTA to more of their patients Early evidence of "adoption phase" Trial-ers Adopters

IN MARKET RESEARCH, PHYSICIANS PERCEIVE PATIENTS ARE EXPERIENCING BENEFIT1 Manifestations of SLE Symptoms Triggering BENLYSTA Prescription ~ % of Patients Fatigue 86% Arthritis 83% Rash 62% Anti-dsDNA Positive 61% Inability to Taper Steroids 56% Low Complement Level 42% Hematologic 39% Serositis 37% Renal 20% CNS 8% Other 5% 7 7% Unchanged 90% Improved 2% Worsened Source: Physician Pulse Study, Fielded February 8-16, n=81 rheumatologists, n=127 patients treated with BENLYSTA for greater than 3 months 1 Physician perceptions from actual use do not necessarily reflect efficacy observed in placebo-controlled clinical trials 2% Mixed Percent of Patients with Benefit in At Least One Manifestation Following At Least 3 Months of BENLYSTA Treatment

Moderate 45% Severe 22% Initial Target: 200,000 Patients Over the Course of Their Disease2,3 Estimated 1,500,000 Patients with Lupus and Related Conditions in the U.S.1 325,000 SLE Patients Treated by Rheumatologists2 8 1 Per Lupus Foundation of America 2 Per HGS primary market research 3 Within BENLYSTA approved indication Mild 33% BENLYSTA(r) IS A BLOCKBUSTER IN PROGRESS Initial Total Addressable U.S. Market 200,000 Patients x $35,000 Price = $7 Billion

PIPELINE PROVIDES UPSIDE OPPORTUNITY FOR OUR SHAREHOLDERS 9 Raxibacumab Inhalation Anthrax3 BENLYSTA(r) Systemic Lupus1, 2 Type 2 Diabetes Albiglutide Darapladib Cardiovascular Disease Marketed BENLYSTA Vasculitis4 BENLYSTA Active Lupus Nephritis4 Alzheimer's Disease Rilapladib

First in class small molecule inhibitor of Lp-PLA2, an enzyme associated with formation of atherosclerotic plaques Target implicated in the inflammatory component of plaque formation Large epidemiological trials have identified Lp-PLA2 as an independent risk factor (from LDL cholesterol) for coronary heart disease and ischemic stroke GSK is committing capital and resources to developing darapladib GSK management has placed emphasis on darapladib The combined Phase 3 clinical program for darapladib is one of the largest ever conducted to evaluate any cardiovascular medication Two Phase 3 registration studies ongoing to determine whether darapladib can reduce future cardiovascular events versus existing standard of care therapy STABILITY study: ~15,800 patients with chronic coronary artery disease; initiated in December 2008 and now fully enrolled SOLID-TIMI 52: >13,000 patients with acute coronary syndrome (ACS); initiated in December 2009 and now fully enrolled If commercialized, HGS will earn 10% royalty on WW sales and has a 20% co- promotion / profit-share option in North America and Europe DARAPLADIB - DISCOVERED BY GSK USING HGS TECHNOLOGY 10

2011 WW Branded Statins and Plavix Markets ($ in billions) Addressable Patient Population (millions) DARAPLADIB - A MULTI-BILLION DOLLAR PRODUCT OPPORTUNITY 11 If approved, darapladib would provide a new option for reducing the risk of adverse CV events Significant market opportunity across a range of disease settings: Patients on statins: additive therapy to reduce plaque formation and CV event risk Patients with ACS: reduce risk of another acute CV event Patients who are statin intolerant: alternative therapy to reduce plaque formation and CV event risk Preventive therapy: alternative therapy to lower risk of CV disease

OTHER PIPELINE OPPORTUNITIES - BALANCED PORTFOLIO OF PARTNERED AND WHOLLY OWNED PRODUCT CANDIDATES 12 Raxibacumab for inhalation anthrax Monoclonal antibody generating revenue under U.S. government contract Albiglutide for Type 2 diabetes (T2D) Once weekly GLP-1 agonist discovered by HGS and licensed to GSK Initial Phase 3 data available with additional studies reporting in 2012; progressing towards WW regulatory filings HGS to receive milestones and royalties (net single digit royalties on WW sales) Will compete vs. Victoza and Byetta/Bydureon in GLP-1 market Rilapladib for Alzheimer's disease Small molecule inhibitor of Lp-PLA2 discovered by GSK using HGS technology GSK is conducting a Phase 2 biomarker study in Alzheimer's disease If commercialized, HGS will receive 10% royalties on WW sales and has a 20% co- promotion option in North America and Europe Mapatumumab for cancer Monoclonal antibody to TRAIL receptor Randomized Phase 2 study ongoing in advanced hepatocellular carcinoma (HCC) HGS has worldwide rights ex-Japan HGS1036 for cancer Biologic to human fibroblast growth factor (FGF) Phase 1b combination studies to begin in 2012 in multiple solid tumors In-licensed from FivePrime; HGS maintains rights in the US, Canada and EU

Significant NOL value $2.4 billion in net operating losses (NOLs) are a valuable tax asset Strong balance sheet Cash on hand of $799 million provides capital base for continued BENLYSTA launch, pipeline execution and near-term debt maturity $207 million 2.25% Convertible Notes due August 2012 $495 million 3% Convertible Notes due 2018 World class biologics manufacturing capabilities Currently manufacture worldwide BENLYSTA commercial product with sufficient capacity for 2-3 years of future growth Partnership with Lonza to triple BENLYSTA manufacturing capacity NOTABLE OPERATIONAL AND FINANCIAL ASSETS 13

NO ADVERSE CHANGE-OF-CONTROL PROVISIONS TIED TO GSK PARTNERSHIP 14 In change of control, all of HGS' rights flow to acquiror Full transferability of BENLYSTA, darapladib, albiglutide and rilapladib rights and economics to a third party acquiror No loss of economic or operational control relative to status quo BENLYSTA 50% co-promotion / profit share and equal HGS operational rights remain unchanged Potential royalties from GSK on approved products remain unchanged 20% co-promotion / profit share option for darapladib and rilapladib in North America and Europe remains unchanged

We remain confident in the future potential of HGS and our Board is committed to maximizing shareholder value BENLYSTA - a blockbuster in progress Darapladib - a blockbuster in the making Upon a change of control, our financial and commercial rights to all programs are fully transferable Pipeline represents a significant upside opportunity for shareholders Balance sheet is strong - $799 million cash and $701 million debt $2.4 billion NOLs Unsolicited GSK proposal does not capture the inherent value of HGS HGS does not intend to discuss the status of its strategic review unless and until a specific transaction has been approved SUMMARY OF HGS VALUE PROPOSITION 15