Human Genome Sciences, Inc. (HGSI) announced the results of its randomized phase 2 trial of mapatumumab (HGS-ETR1) in combination with bortezomib (Velcade) in patients with advanced multiple myeloma.

The results showed no difference in disease response or progression-free survival for the combination that included mapatumumab vs. the control group receiving bortezomib alone, and showed that mapatumumab was well tolerated in this study. HGS expects to present the results in full at an appropriate scientific meeting, hopefully later in 2010.

Mapatumumab is an agonistic human monoclonal antibody that directly induces cancer cell death by specifically binding to and activating the protein known as TRAIL receptor 1. A randomized phase 2 trial is currently underway to evaluate mapatumumab’s potential, in combination with Nexavar (sorafenib), in the treatment of advanced hepatocellular cancer. HGS expects to initiate the randomization stage of the hepatocellular cancer study before the end of 2010.

The company is investing strategically to expand and advance its oncology portfolio around its expertise in the apoptosis, or programmed cell death, pathway. In November 2009, HGS and Aegera Therapeutics announced the initiation of a phase 1 trial of HGS’ lead IAP inhibitor, HGS1029, as monotherapy in patients with advanced lymphoid tumours. HGS1029 as monotherapy is also being studied in an ongoing phase 1 study initiated in 2008 in patients with advanced solid tumours. The IAP inhibitors are a novel class of compounds that block the activity of IAP (inhibitor of apoptosis) proteins, allowing apoptosis to proceed and causing the cancer cells to die. When IAP proteins are over-expressed in cancer cells, they can help cancer cells resist apoptosis and resume growth and proliferation. HGS plans to continue the study of HGS1029 both alone and in combination with other anti-cancer agents, including mapatumumab.