Human Genome Sciences and Aegera Therapeutics Announce Initiation of Clinical Trial of Lead IAP Inhibitor HGS1029 in Advanced Lymphoid Tumors

Human Genome Sciences, Inc. (Nasdaq: HGSI) and Aegera Therapeutics, Inc. today announced that HGS has initiated dosing in a Phase 1 clinical trial to evaluate the safety and tolerability of its lead IAP inhibitor, HGS1029, as monotherapy in patients with advanced lymphoid tumors.

"We are pleased to initiate this first human study of HGS1029 in lymphoid malignancies, and we look forward to continuing the study of our IAP inhibitors both alone and in combination with other anti-cancer agents, including mapatumumab, our agonistic antibody to TRAIL receptor 1,” said Gilles Gallant, B. Pharm., Ph.D., Vice President, Clinical Research - Oncology, HGS. An additional Phase 1 clinical trial is currently ongoing to evaluate the safety and tolerability of HGS1029 in patients with advanced solid tumors.

"Our collaboration with Human Genome Sciences is progressing very well,” said Michael J. Berendt, Ph.D., President and Chief Executive Officer, Aegera Therapeutics. "We continue to believe that the combination of our extensive knowledge of the control of apoptotic pathways with HGS’s deep understanding of the development of targeted therapeutics will speed the development of HGS1029 and follow-on compounds for multiple oncology indications.”

HGS acquired exclusive worldwide rights (excluding Japan) to develop and commercialize HGS1029 and other IAP inhibitors from Aegera Therapeutics, Inc. in December 2007. When inhibitor-of-apoptosis proteins (IAP’s) are over-expressed in cancer cells, they may help cancer cells resist apoptosis, or programmed cell death, and resume growth. The IAP inhibitors developed by Aegera, including HGS1029, are members of a new class of designed small-molecule drugs that block the biological activity of IAP’s, thus allowing apoptosis to proceed and causing the cancer cells to die. Preclinical studies have shown that HGS1029 has significant anti-tumor activity alone and in combination with other anti-cancer agents, including the HGS TRAIL receptor antibodies, against a number of cancer types.

About the Phase 1 Trial Design

The primary objectives of the Phase 1 open-label, dose-escalation study are to evaluate the safety and tolerability of HGS1029 as monotherapy in patients with advanced lymphoid tumors, and to select a recommended dose for Phase 2 studies. Secondary objectives include documenting possible anti-tumor activity and determining HGS1029’s pharmacokinetic profile. HGS1029 will be administered as a 15-minute intravenous infusion once weekly for 3 consecutive weeks followed by a week off.

About Aegera Therapeutics

Aegera Therapeutics is a clinical stage biotechnology company focused on developing targeted therapeutics to address major unmet medical needs. In addition to HGS1029 (AEG40826), Aegera has the following programs in clinical development:

AEG35156 is a DNA antisense oligonucleotide that targets the key anti-apoptotic protein XIAP, and is currently in multiple Phase 2 human clinical trials for the treatment of solid tumors and hematological malignancies; and

AEG33773 is a first-in-class oral small molecule HSP90 modulator, which is in Phase 2a development for the treatment of painful diabetic neuropathy in North American and Europe.

For more information, please visit the Aegera website at www.aegera.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.

The Company’s primary focus is rapid progress toward the commercialization of its two lead drugs, BENLYSTA™ (belimumab) for lupus and ZALBIN™ (albinterferon alfa-2b) for hepatitis C. Phase 3 development has been completed successfully for both BENLYSTA and ZALBIN. The submission of marketing applications for BENLYSTA is planned in the U.S., Europe and other regions in the first half of 2010. The submission of global marketing applications for ZALBIN is planned in fourth quarter 2009.

In April 2009, HGS completed the delivery of 20,000 doses of raxibacumab to the U.S. Strategic National Stockpile for use in the event of an emergency to treat inhalational anthrax. In July 2009, HGS secured a new purchase order for 45,000 doses of raxibacumab to be delivered to the Stockpile over a three-year period beginning near the end of 2009. In May 2009, HGS submitted a Biologics License Application to the FDA for raxibacumab for the treatment of inhalation anthrax.

The Company also has several drugs in earlier stages of clinical development for the treatment of cancer, led by the TRAIL receptor antibody mapatumumab and a small-molecule antagonist of inhibitor-of-apoptosis proteins (IAP’s). In addition, HGS has substantial financial rights to certain products in the GSK clinical pipeline including darapladib, currently in Phase 3 development in patients with coronary heart disease, and Syncria® (albiglutide), currently in Phase 3 development in patients with type 2 diabetes.

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.

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, 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.