Human Genome Sciences Inc has received a clinical trial exemption (CTX) from the United Kingdom's Medicines and Healthcare products Regulatory Agency allowing the Company to begin clinical development of an agonistic human monoclonal antibody to TRAIL Receptor-2 (TRAIL-R2 mAb, HGS-ETR2). The Company now plans to proceed with a Phase 1 open-label, dose-escalating study in the United Kingdom to evaluate the safety and pharmacology of TRAIL-R2 mAb in patients with advanced tumors.

Company scientists will present the results of several in vitro and in vivo preclinical studies providing evidence that TRAIL-R2 mAb is an attractive candidate for development as a potential treatment for various cancers, at the 94th annual meeting of the American Association for Cancer Research. These data demonstrate that TRAIL-R2 mAb specifically binds to TRAIL Receptor-2, induces apoptosis and has anti-tumor activity in a broad range of tumor types, both as a single agent and in combination with chemotherapy.

Human Genome Sciences originally identified the TRAIL Receptor-2 protein as a member of the tumor necrosis factor family of proteins. Human Genome Sciences' own studies, as well as those of others, show that TRAIL Receptor-2 is expressed on a number of solid tumors and tumors of hematopoietic origin. It has been demonstrated that many such tumors are sensitive to killing by apoptosis induced by binding to TRAIL (tumor necrosis factor-related apoptosis-inducing ligand) and by binding to TRAIL-R2 mAb1, 2. TRAIL-R2 mAb mimics the activity of native TRAIL. As such, it is considered an agonistic antibody.

TRAIL-R2 mAb is the fifth drug that Human Genome Sciences has in clinical development for use in cancer therapy. The other drugs include LymphoRad for the treatment of B-cell cancers, TRAIL-R1 mAb for the treatment of solid tumors and tumors of hematopoietic origin, Albuleukin for the treatment of solid tumors, and repifermin for the treatment of cancer therapy-induced mucositis. The Phase 1 clinical trial of TRAIL-R2 mAb will be Human Genome Sciences' first clinical trial to be conducted in Europe.

The TRAIL-R2 agonistic human monoclonal antibody was made in a collaboration between Human Genome Sciences and Cambridge Antibody Technology. The drug will be produced in the Human Genome Sciences clinical manufacturing facility located in Rockville, Maryland. Human Genome Sciences holds the commercial rights to the drug.

Human Genome Sciences also has a license agreement with the Pharmaceutical Division of Kirin Brewery Company, Ltd., under which Human Genome Sciences and Kirin are collaborating on the development and commercialization of agonistic human monoclonal antibodies to TRAIL Receptor-2.