HUMAN GENOME SCIENCES AND BIOINVENT ANNOUNCE COLLABORATION TO CO-DEVELOP AND COMMERCIALIZE THERAPEUTIC ANTIBODIES

HUMAN GENOME SCIENCES AND BIOINVENT ANNOUNCE COLLABORATION TO CO-DEVELOP AND COMMERCIALIZE THERAPEUTIC ANTIBODIES

ROCKVILLE, Maryland and LUND, Sweden - March 11, 2010 - Human Genome Sciences, Inc. (Nasdaq: HGSI) and BioInvent International AB (OMXS: BINV) today announced that they have entered into a collaboration to discover, develop and commercialize therapeutic monoclonal antibodies that specifically target antigens discovered by HGS.

Under the terms of the agreement, BioInvent will apply its state-of-the art antibody discovery technology to generate and develop monoclonal antibody candidates. The collaboration will initially focus on the development of antibodies in the field of inflammation. HGS and BioInvent will each have the right to participate in development and global commercialization of each antibody candidate, and will share research, development, manufacturing and commercialization costs as well as future revenues. Specific terms were not disclosed.

"We continue to make excellent progress in advancing our late-stage products toward commercialization, and at the same time we remain committed to building and advancing our research pipeline to ensure sustainable growth well into the future," said H. Thomas Watkins, President and Chief Executive Officer, HGS. "We look forward to collaborating with BioInvent to apply their proprietary technology to the development of targeted new therapies based on HGS discoveries."

Svein Mathisen, Chief Executive Officer of BioInvent, said, "Access to commercially attractive targets to which we can apply our antibody discovery engine is an important part of BioInvent's strategy. We believe this collaborative agreement is a strong and valuable way of building our pipeline of innovative drugs as BioInvent and HGS's research strengths are both complementary and synergistic. We are looking forward to working closely with HGS in what we believe will be a long-term, productive collaboration."

About the BioInvent Proprietary Antibody Discovery Platform

BioInvent's proprietary antibody discovery platform, n-CoDeR®, contains over 20 billion (2 x1010) human antibody genes, a far greater number than those naturally available in the human immune system. This provides a greater likelihood of finding antibodies with both high affinity and specificity against a particular target. BioInvent has a broad and innovative portfolio of therapeutic antibodies, with four products currently in clinical development in the fields of thrombosis, atherosclerosis and cancer.

About the HGS New Targets Initiative

HGS has a rich heritage of scientific discovery that has produced a large intellectual property estate and a library of thousands of therapeutic and diagnostic targets. HGS has conducted a careful review and selected a number of targets for further research and potential development. HGS plans to develop the selected targets through its own internal research, as well as through research collaborations, including the agreement with BioInvent announced today.

About BioInvent

BioInvent International AB, listed on the NASDAQ OMX Stockholm (BINV), is a research-based pharmaceutical company that focuses on developing antibody drugs. BioInvent currently has four clinical development projects within the areas of thrombosis, cancer and atherosclerosis. BioInvent has signed various strategic alliances around these product candidates and is developing them in collaboration with partners including Genentech, Roche and ThromboGenics.

These projects are based around a competitive and in substance patented antibody development platform. The scope and strength of this platform is also utilized by partners, such as ALK-Abelló, Bayer HealthCare, Daiichi Sankyo, ImmunoGen, Mitsubishi Tanabe, OrbusNeich, UCB and XOMA. More information is available at www.bioinvent.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.

HGS's primary focus is rapid progress toward the commercialization of its two lead drugs, BENLYSTATM (belimumab) for systemic lupus and ZALBINTM (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 second quarter of 2010. A BLA has been submitted for ZALBIN to the FDA in the United States, and an MAA has been submitted under the brand name JOULFERON® to the EMEA in Europe.

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 inhalation anthrax. In July 2009, HGS secured a new purchase order for 45,000 doses, and delivered the first 5,600 doses to the Stockpile under the new order in November 2009. HGS also has several drugs in earlier stages of development for treatment of cancer, led by the TRAIL receptor antibody mapatumumab and a small-molecule antagonist of inhibitor-of-apoptosis proteins. In addition, HGS has substantial financial rights to certain products in the GSK clinical pipeline including darapladib, in Phase 3 development in patients with coronary heart disease, and Syncria® (albiglutide), 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 [email protected] 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, BENLYSTA, and ZALBIN 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, 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.