Exhibit 99

PRESS RELEASE

Media Contacts:		Investor Contacts:
Jerry Parrott		Claudine Prowse, Ph.D.
Vice President, Corporate Communications		Executive Director, Investor Relations
301-315-2777		301-315-1785
Susannah Budington		Peter Vozzo
Director, Corporate Public Relations		Senior Director, Investor Relations
301-545-1062		301-251-6003

HUMAN GENOME SCIENCES ANNOUNCES FOURTH-QUARTER AND FULL-YEAR FINANCIAL RESULTS AND KEY DEVELOPMENTS

	•		By a 13-2 vote in November 2010, the FDA Arthritis Advisory Committee recommended approval of BENLYSTA® for the treatment of systemic lupus erythematosus; the FDA decision is expected by March 10, 2011
	•		A decision from the European Medicines Agency on the BENLYSTA Marketing Authorization Application submitted in June 2010 is anticipated in the second half of 2011
	•		HGS ended 2010 with $933 million in cash and investments

ROCKVILLE, Maryland — February 24, 2011 — Human Genome Sciences, Inc. (Nasdaq: HGSI) today announced financial results for the quarter and full year ended December 31, 2010, and provided highlights of recent key developments.

“2010 was a pivotal year in Human Genome Sciences’ progress toward becoming a fully commercial organization with sustainable revenues and growth,” said H. Thomas Watkins, President and Chief Executive Officer. “The FDA Arthritis Advisory Committee recommended by a vote of 13-2 in November that FDA approve BENLYSTA for the treatment of systemic lupus. We now look forward to having the FDA’s decision by March 10, 2011. If the decision is favorable, BENLYSTA would be the first new drug approved for systemic lupus in more than fifty years for patients and those who treat them. The approval of BENLYSTA would open the door to a promising future.”

FINANCIAL RESULTS

HGS reported revenues of $157.4 million for the year ended December 31, 2010, compared with revenues of $275.7 million for 2009. Revenues for 2010 included $82.8 million recognized from the ZALBIN™ agreement with Novartis, including recognition of all remaining deferred revenue for payments previously received under the agreement; $47.2 million recognized from the sale and delivery of raxibacumab to the U.S. Strategic National Stockpile; and $21.3 million recognized from manufacturing and development services other than raxibacumab. The decrease in revenues for 2010 primarily reflected the higher level of raxibacumab revenue recognized in 2009, $180.2 million, partially offset by increased recognition of revenue from the ZALBIN agreement in 2010.

The Company reported a net loss for 2010 of $233.2 million ($1.24 per share), compared with net income of $5.7 million ($0.04 per share) for 2009. The change from net income to net loss was primarily due to lower product sales and manufacturing and development services revenue in 2010 versus 2009, in addition to a gain in 2009 of $38.9 million on the extinguishment of debt, partially offset by increased revenue recognized from the ZALBIN agreement with Novartis in 2010.

As of December 31, 2010, cash and investments totaled $933.4 million, of which $853.9 million was unrestricted and available for operations. This compares with cash and investments totaling $1.2 billion as of December 31, 2009, of which $1.1 billion was unrestricted and available for operations.

For the fourth quarter ended December 31, 2010, HGS reported revenues of $21.3 million, compared with revenues of $53.0 million for the same period in 2009. Fourth quarter 2010 revenues primarily included $13.2 million recognized from sales and deliveries of raxibacumab to the U.S. Strategic National Stockpile and $7.5 million recognized from manufacturing and development services other than raxibacumab.

The Company’s net loss for the quarter ended December 31, 2010 increased to $87.6 million ($0.46 per share), compared with a net loss of $9.7 million ($0.06 per share) for the fourth quarter of 2009. The increase in net loss was primarily due to the decrease described above in raxibacumab revenue, decreased ZALBIN revenue and increased expenses related to the potential launch of BENLYSTA.

“With more than $933 million in cash and investments, HGS has the financial strength required to support a world-class launch of BENLYSTA while continuing to advance and broaden our research and development pipeline,” said David Southwell, Executive Vice President and Chief Financial Officer.

HIGHLIGHTS OF RECENT PROGRESS

BENLYSTA^®: FDA Approval Recommended by Advisory Committee; PDUFA Target Date for FDA Decision Extended to March 10, 2011; On Track for Launch Assuming Approval

In November 2010, the FDA Arthritis Advisory Committee voted 13-2 to recommend that the FDA approve BENLYSTA (belimumab) for the treatment of autoantibody-positive patients with active SLE who are receiving standard therapy. In December 2010, the FDA extended the Prescription Drug User Fee Act (PDUFA) target date for the priority review of BENLYSTA to March 10, 2011. HGS and GSK expect to receive a decision on European approval of BENLYSTA in the second half of 2011, and GSK also has submitted regulatory applications in Canada, Australia, Switzerland, Russia, Brazil and The Philippines. No new drug for lupus has been approved by regulatory authorities in more than 50 years. BENLYSTA is being developed by HGS and GSK under a co-development and commercialization agreement entered into in 2006.

In 2010, HGS substantially increased its investment in the commercial infrastructure, expertise and product manufacture required to launch and support BENLYSTA, assuming it receives regulatory approval as anticipated. In the U.S., the combined HGS and GSK team, including a U.S. sales force of approximately 150, will work closely together following approval to communicate the appropriate use of BENLYSTA to rheumatologists and other stakeholders. HGS and GSK also plan to support patients with reimbursement and access programs. In Europe, HGS is building its own commercialization team to work with GSK, with HGS headquarters in Switzerland and local organizations in Germany, France and Spain. Elsewhere outside the U.S., GSK will lead local implementation, with HGS sharing costs and profits equally with GSK.

During 2010, HGS also continued to manufacture BENLYSTA and build product inventory to meet global demand for BENLYSTA upon receiving regulatory approvals. HGS believes it currently has inventory available to meet global market needs for at least one year, and its large-scale manufacturing facility has sufficient capacity to provide worldwide supply for the first two to three years following launch. In July 2010, HGS announced an agreement with Lonza that will support future sales of BENLYSTA — eventually tripling capacity — with production expected to come on line in 2012.

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

In 2010, HGS continued delivery of raxibacumab to the U.S. Strategic National Stockpile. In July 2009, the U.S. Government exercised its option to purchase 45,000 additional doses of raxibacumab for the 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 $64.9 million received through December 31, 2010. 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).

FINANCIAL GUIDANCE

HGS expects cash and investments at year-end 2011 to total between $550 million and $650 million. Cash and investments were $933.4 million at year-end 2010.

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 e-mail to medinfo@hgsi.com or by calling HGS at (877) 822-8472. HGS, Human Genome Sciences, BENLYSTA and ZALBIN are trademarks of Human Genome Sciences, Inc. Other trademarks referenced are the property of their respective owners.

SAFE HARBOR STATEMENT

This announcement contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. The forward-looking statements are based on Human Genome Sciences’ current intent, belief and expectations. These statements are not guarantees of future performance and are subject to certain risks and uncertainties that are difficult to predict. Actual results may differ materially from these forward-looking statements because of Human Genome Sciences’ unproven business model, its

dependence on new technologies, the uncertainty and timing of clinical trials and regulatory approvals, Human Genome Sciences’ ability to develop and commercialize products, its dependence on collaborators for services and revenue, its substantial indebtedness and lease obligations, its changing requirements and costs associated with facilities, intense competition, the uncertainty of patent and intellectual property protection, Human Genome Sciences’ dependence on key management and key suppliers, the uncertainty of regulation of products, the impact of future alliances or transactions and other risks described in the Company’s filings with the SEC. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of today’s date. Human Genome Sciences undertakes no obligation to update or revise the information contained in this announcement whether as a result of new information, future events or circumstances or otherwise.

HUMAN GENOME SCIENCES, INC.
CONSOLIDATED STATEMENTS OF OPERATIONS

		Three months ended December 31,								Twelve months ended December 31,
		2010				2009				2010				2009
		(dollars in thousands, except share and per share amounts)
Revenue:
Product sales		$	13,196			$	17,693			$	47,159			$	154,074
Manufacturing and development services			7,517				5,360				22,695				50,653
Research and development collaborative agreements			549				29,904				87,497				71,022
Total revenue			21,262				52,957				157,351				275,749
Costs and expenses:
Cost of product sales			6,411				1,236				29,941				15,805
Cost of manufacturing and development services			7,652				976				15,016				18,215
Research and development expenses			45,039				42,330				196,370				173,709
General and administrative expenses			38,341				19,319				106,797				61,073
Facility-related exit charges (credits) (a)			—				(10,675	)			—				759
Total costs and expenses (b)			97,443				53,186				348,124				269,561
Income (loss) from operations			(76,181	)			(229	)			(190,773	)			6,188
Investment income			3,469				3,623				16,966				12,727
Interest expense			(15,091	)			(14,465	)			(59,500	)			(58,424	)
Gain on extinguishment of debt			—				—				—				38,873
Gain on sale of long-term equity investment			—				—				—				5,259
Other income (expense)			171				56				76				(238	)
Income (loss) before taxes			(87,632	)			(11,015	)			(233,231	)			4,385
Income tax benefit			—				1,274				—				1,274
Net income (loss)		$	(87,632	)		$	(9,741	)		$	(233,231	)		$	5,659
Basic net income (loss) per share		$	(0.46	)		$	(0.06	)		$	(1.24	)		$	0.04
Diluted net income (loss) per share		$	(0.46	)		$	(0.06	)		$	(1.24	)		$	0.04
Weighted average shares outstanding, basic			188,896,481				170,700,803				187,791,437				149,334,426
Weighted average shares outstanding, diluted			188,896,481				170,700,803				187,791,437				155,053,473

CONSOLIDATED BALANCE SHEET DATA:

		As of				As of
		December 31, 2010				December 31, 2009
		(dollars in thousands)
Cash, cash equivalents and investments (c)		$	933,382			$	1,191,660
Total assets (c)			1,315,029				1,530,630
Convertible subordinated debt (d)			372,851				349,807
Lease financing			250,516				248,628
Total stockholders’ equity			585,763				755,415

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