- Poster presentations at EULAR of data from the BLISS-52 study in patients with seropositive systemic lupus erythematosus (SLE) will report that belimumab, compared with placebo in this study, significantly reduced SLE disease activity; significantly improved physical functioning and other health-related quality of life measures; significantly reduced autoantibodies; and normalized low complement -

ROCKVILLE, Maryland, and LONDON, UK – June 17, 2010 – Human Genome Sciences, Inc. (Nasdaq: HGSI) and GlaxoSmithKline PLC (GSK) today announced the presentation of additional results from BLISS-52, one of two pivotal Phase 3 trials of BENLYSTA® (belimumab) in seropositive patients with systemic lupus erythematosus (SLE). The additional data will be presented in Rome at the 2010 Congress of the European League against Rheumatism (EULAR) on Saturday, June 19.

“The BLISS-52 Phase 3 results presented at EULAR demonstrate that the efficacy of treatment in this study with belimumab plus standard of care was superior to that of placebo plus standard of care,” said David C. Stump, M.D., Executive Vice President, Research and Development, HGS. “Belimumab has met the primary endpoint in both of its pivotal Phase 3 trials. Earlier this month, we and GSK submitted marketing applications for belimumab in the United States and Europe. We now look forward to the consideration and conclusions of regulatory authorities.”

Carlo Russo, M.D., Senior Vice President, Biopharm Development, GSK, said, “With both of the pivotal Phase 3 trials completed successfully, the results presented at major scientific meetings and regulatory applications now under review, we very much hope that we will be able to deliver a new option for the treatment of systemic lupus.”

Belimumab is an investigational drug and the first in a new class of drugs called BLyS-specific inhibitors. It is being developed by HGS and GSK under a co-development and commercialization agreement entered into in 2006. GSK submitted a Marketing Authorization Application to the European Medicines Agency on June 4, 2010, seeking approval to market belimumab in Europe for treatment of autoantibody-positive patients with SLE. On June 10, 2010, HGS announced submission of a Biologics License Application (BLA) to the U.S. Food and Drug Administration seeking approval to market belimumab in the United States. No new drug for lupus has been approved by regulatory authorities in more than 50 years.

KEY FINDINGS PRESENTED AT EULAR FROM THE BLISS-52 PHASE 3 STUDY

At EULAR on Saturday June 19, three poster presentations will provide results from the BLISS-52 Phase 3 trial of belimumab in seropositive patients with SLE.

BLISS-52 Patient Response Rates (SRI)

BLISS-52 data previously presented at the Annual Scientific Meeting of the American College of Rheumatology (ACR) in October 2009, demonstrated that belimumab plus standard of care met the primary endpoint of the study by achieving a statistically significant improvement in patient response rate as measured by the SLE Responder Index (SRI) at Week 52, compared with placebo plus standard of care. 

• The SRI defines patient response by an improvement in SELENA SLEDAI score of 4 points or greater, with no clinically significant BILAG worsening, and no clinically significant worsening in Physician’s Global Assessment.
• A clinically and statistically significant improvement was shown in SRI response rate for belimumab plus standard of care vs. placebo plus standard of care: 57.6% for 10 mg/kg belimumab, 51.4% for 1 mg/kg belimumab, and 43.6% for placebo (p=0.0006 and p=0.013 for 10 mg/kg and 1 mg/kg belimumab, respectively). 
• There were more responders in the 10 mg/kg belimumab group compared to the placebo group between Weeks 4 and 8 of the study and this difference was statistically significant at Week 16 (p<0.05 for 10 mg/kg belimumab vs. placebo). The improvement was statistically significant and sustained for 10 mg/kg and 1 mg/kg belimumab from Week 24 and Week 28, respectively, through 52 weeks (p<0.05 for both belimumab treatment groups). 
• Post hoc exploratory analyses to be presented at EULAR evaluated SRI response in BLISS-52 using greater SELENA SLEDAI reductions (-5, -6, or -7 or more points) than the 4-point reduction used for the primary endpoint. These results along with the pre-specified 4-point reduction are provided below. Using these higher SELENA SLEDAI thresholds, a greater treatment effect was observed, with improvements in SRI response for both belimumab treatment groups at Week 52.

Key BLISS-52 Findings Presented at EULAR
 

Steroid Use

• In patients who were receiving prednisone at baseline, a significantly higher percentage of patients in the 10 mg/kg belimumab treatment group vs. the placebo group had their average prednisone dose reduced by at least 50% from Weeks 24-52 (all p<0.05). A higher percentage of patients in the 1 mg/kg belimumab treatment group vs. the placebo group also had their average prednisone dose reduced by at least 50% after Week 24, but the difference reached a level of statistical significance only at Week 32 (p=0.036).

Biomarker Data 

• Among patients who were positive for autoantibodies at baseline, significantly greater median percent reductions in autoantibodies were observed in the belimumab treatment groups by Week 52, vs. placebo, including: reductions in anti-dsDNA of 37.6% for belimumab 10 mg/kg, 35.1% for belimumab 1 mg/kg, and 12.3% for placebo (p<0.001 for both doses); reductions in anti-Smith of 56.3% for belimumab 10 mg/kg, 47.0% for belimumab 1 mg/kg, and 29.6% for placebo (p=0.0001 and p=0.0042 for belimumab 10 mg/kg and 1 mg/kg, respectively); and anti-ribosomal P of 55.6% for belimumab 10 mg/kg, 35.7% for belimumab 1 mg/kg, and 5.0% for placebo (p<0.0001 and p=0.019 for belimumab 10 mg/kg and 1 mg/kg, respectively). 
• A significantly greater percentage of belimumab-treated patients with hypergammaglobulinemia at baseline achieved normalization of IgG at Week 52 (p<0.05). Significantly greater median percent reductions in immunoglobulins were observed in the belimumab treatment groups by Week 52 (with p<0.0001 for both belimumab doses, vs. placebo), including: reductions in IgG of 15.6% for belimumab 10 mg/kg, 14.1% for belimumab 1 mg/kg, and 3.6% for placebo; reductions in IgM of 30.0% for belimumab 10 mg/kg, 28.5% for belimumab 1 mg/kg, and 3.2%% for placebo; and reductions in IgA of 16.0% for belimumab 10 mg/kg, 16.8% for belimumab 1 mg/kg, and 2.7% for placebo. 
• Among patients with low C3 and C4 complement at baseline, significantly greater median percent increases were observed among patients in the belimumab treatment groups vs. the placebo group, with increases observed by Weeks 4-8 that were sustained or increased through Week 52. At Week 52, the median percent increase from baseline in C3 complement was 16.3% for belimumab 10 mg/kg, 10.1% for belimumab 1 mg/kg, and 2.1% for placebo (p<0.0001 and p=0.0061 for belimumab 10 mg/kg and 1 mg/kg, respectively, vs. placebo). At Week 52, the median percent increase from baseline in C4 complement was 50.0% for belimumab 10 mg/kg, 42.9% for belimumab 1 mg/kg, and 12.5% for placebo (p<0.0001 for both belimumab doses, vs. placebo).

Additional BLISS-52 Efficacy Data

• Disease activity and flares: The EULAR presentation included BLISS-52 data previously presented at ACR, which demonstrated that belimumab 10 mg/kg also significantly reduced disease activity as measured by SELENA SLEDAI scores and Physicians Global Assessment (PGA); significantly delayed time to severe flare and significantly reduced the risk of 1 BILAG A (severe) organ flare or more than 1 BILAG B (moderate) organ flare.
• Fatigue and health-related quality of life (HRQOL): The EULAR presentation included previously presented BLISS-52 data, which demonstrated that, in both belimumab treatment groups vs. placebo, significantly greater improvements were achieved by Week 52 in FACIT-Fatigue scores and in SF-36 Health-Related Quality-of-Life Physical Component Summary (PCS), Physical Functioning and Bodily Pain scores.

Safety

• In BLISS-52, belimumab was generally well tolerated, with rates of adverse events overall, serious and/or severe adverse events, all infections, serious and/or severe infections, and discontinuations due to adverse events comparable between treatment groups receiving belimumab plus standard of care and the treatment group receiving placebo plus standard of care. Serious and/or severe adverse events were reported in 18.5% of patients on belimumab and 16.7% of patients on placebo. Infections were reported in 67.6% of patients on belimumab and 63.8%% of patients on placebo. Serious and/or severe infections were reported in 6.2% of patients on belimumab and 6.3% of patients on placebo. Serious and/or severe infusion reactions were reported in 1.6% of patients on belimumab and 0.3% of patients on placebo. Discontinuations due to adverse events were 5.4% in the belimumab treatment groups and 6.6% in the placebo treatment group. No malignancies were reported. A total of 9 deaths were reported in the study: 4, 2, and 3 in the belimumab 10 mg/kg, belimumab 1 mg/kg and placebo groups, respectively.

About the BENLYSTA (belimumab) Phase 3 Development Program

The Phase 3 development program for belimumab included two double-blind, placebo-controlled, multi-center Phase 3 superiority trials – BLISS-52 and BLISS-76 – to evaluate the efficacy and safety of belimumab plus standard of care, versus placebo plus standard of care, in seropositive (HEp-2 ANA > 1:80 and/or anti-dsDNA > 30 IU/mL) patients with SLE. Both BLISS-52 and BLISS-76 have now been completed. This is the largest clinical trial program ever conducted in lupus patients. BLISS-52 randomized and treated 865 patients at 90 clinical sites in 13 countries, primarily in Asia, South America and Eastern Europe. BLISS-76 randomized and treated 819 patients at 136 clinical sites in 19 countries, primarily in North America and Europe.

The design of the two trials was similar, but the duration of therapy in the two studies was different – 52 weeks for BLISS-52 and 76 weeks for BLISS-76. The data from the BLISS-76 Phase 3 study were analyzed after 52 weeks in accord with the study protocol, in support of the BLA and MAA submissions. The BLISS-76 study then continued for an additional 24 weeks through the full 76-week treatment period, with the objective of generating additional information about belimumab based on a variety of secondary endpoints. HGS designed the Phase 3 program for belimumab in collaboration with GSK and leading international SLE experts, and the program is being conducted under a Special Protocol Assessment agreement with FDA.

About BENLYSTA (belimumab)

Belimumab is an investigational human monoclonal antibody drug that specifically recognizes and inhibits the biological activity of B-lymphocyte stimulator, or BLyS. BLyS is a naturally occurring protein discovered by HGS that is required for the development of B-lymphocyte cells into mature plasma B cells. Plasma B cells produce antibodies, the body’s first line of defense against infection. In lupus and certain other autoimmune diseases, elevated levels of BLyS are believed to contribute to the production of autoantibodies – antibodies that attack and destroy the body’s own healthy tissues. The presence of autoantibodies appears to correlate with disease severity. Preclinical and clinical studies suggest that belimumab can reduce autoantibody levels in SLE. The results of two pivotal Phase 3 trials, BLISS-52 and BLISS-76, suggest that belimumab can reduce SLE disease activity.

About the Collaboration with GSK

In 2006, HGS and GSK entered into a definitive co-development and commercialization agreement under which HGS is conducting the belimumab Phase 3 trials, with assistance from GSK. The companies will share equally in Phase 3/4 development costs, sales and marketing expenses, and profits of any product commercialized under the agreement.

About Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic, life-threatening autoimmune disease. Approximately five million people worldwide, including approximately 1.5 million in the United States, suffer from various forms of lupus, including SLE. Lupus can occur at any age, but appears mostly in young people ages 15 to 45. About 90 percent of those diagnosed with lupus are women. African-American women are about three times more likely to develop lupus, and it is also more common in Hispanic, Asian and American Indian women. Symptoms may include extreme fatigue, painful and swollen joints, unexplained fever, skin rash and kidney problems. Lupus can lead to arthritis, kidney failure, heart and lung inflammation, central nervous system abnormalities, inflammation of the blood vessels and blood disorders. No new drug for lupus has been approved by regulatory authorities in more than 50 years. For more information on lupus, visit the Lupus Foundation of America at www.lupus.org, the Lupus Research Institute at www.lupusresearchinstitute.org, the National Institute of Arthritis and Musculoskeletal and Skin Diseases at www.niams.nih.gov, or Lupus Europe at www.elef.rheumanet.org.

About GlaxoSmithKline

GSK Biopharm R&D is employing novel approaches to harness the therapeutic potential of biopharmaceuticals for the benefit of patients with serious autoimmune disease.

GlaxoSmithKline – one of the world’s leading research-based pharmaceutical and healthcare companies – is committed to improving the quality of human life by enabling people to do more, feel better and live longer. For further information please visit http://www.gsk.com/,

About Human Genome Sciences

The mission of HGS is to apply great science and great medicine to bring innovative drugs to patients with unmet medical needs. The HGS clinical development pipeline includes novel drugs to treat lupus, hepatitis C, inhalation anthrax and cancer.

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 This e-mail address is being protected from spam bots, you need JavaScript enabled to view it or by calling HGS at (877) 822-8472.

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

HGS 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.

GlaxoSmithKline Forward-Looking Statements

Under the safe harbor provisions of the US Private Securities Litigation Reform Act of 1995, GSK cautions investors that any forward-looking statements or projections made by GSK, including those made in this announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Factors that may affect GSK's operations are described under 'Risk Factors' in the ‘Business Review’ in GSK's Annual Report on Form 20-F for 2009.

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HGS CONTACTS:

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GSK CONTACTS:

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U.S. Analyst/Investor Inquiries –
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