Seattle Genetics, Agensys present ASG-5ME ADC preclinical data at 101st AACR

Seattle Genetics, Inc. (Nasdaq: SGEN) and Agensys, Inc., an affiliate of Tokyo-based Astellas Pharma Inc., today reported preclinical data with ASG-5ME, an antibody-drug conjugate (ADC) that is being co-developed by both companies for the treatment of solid tumors. In models of human prostate and pancreatic cancer, ASG-5ME was found to have potent and long lasting antitumor activity. The findings were presented at the 101st Annual Meeting of the American Association for Cancer Research (AACR) being held in Washington, D.C.

“The collaboration between Agensys and Seattle Genetics allowed ASG-5ME to advance rapidly toward clinical trials, and we look forward to evaluating the tolerability and antitumor activity of this ADC in cancer indications that are in need of new therapeutic options.”

"ASG-5ME is one of the ADC products in Agensys' pipeline that we are advancing to the clinic. We believe that our ADC products will contribute to Astellas' growing presence in oncology," said Aya Jakobovits, Ph.D., Executive Vice President and Chief Scientific Officer at Agensys. "ASG-5ME is directed to AGS-5, an Agensys proprietary target expressed significantly in patients with prostate, pancreatic and gastric cancers, providing multiple clinical development opportunities."

"We are excited to test the potential of ASG-5ME in patients with prostate and pancreatic cancer," said Jonathan Drachman, M.D., Vice President, Translational Medicine at Seattle Genetics. "The collaboration between Agensys and Seattle Genetics allowed ASG-5ME to advance rapidly toward clinical trials, and we look forward to evaluating the tolerability and antitumor activity of this ADC in cancer indications that are in need of new therapeutic options."

ASG-5ME is an ADC composed of a fully human antibody directed to AGS-5, a novel cancer target discovered by Agensys. The antibody is attached to a potent, synthetic drug payload, monomethyl auristatin E (MMAE), via an enzyme-cleavable linker using Seattle Genetics' proprietary technology. The ADC is designed to be stable in the bloodstream, but to release MMAE upon internalization into AGS-5-expressing tumor cells, resulting in targeted cell-killing.

Data presented at AACR show that AGS-5 is significantly expressed on more than 80 percent of samples derived from patients with prostate, pancreatic and gastric cancers. In preclinical models, ASG-5ME induced long-term regression of established prostate, pancreatic and colon cancer xenografts (Abstracts #2590 and #4393). Seattle Genetics and Agensys expect to initiate phase I clinical trials of ASG-5ME during 2010.

According to the American Cancer Society, more than 192,000 new cases of prostate cancer were diagnosed in the United States during 2009, making it the third most commonly diagnosed form of cancer. More than 27,000 men died of prostate cancer in 2009. The annual incidence of pancreatic cancer is estimated to be greater than 42,000 cases, and more than 35,000 people died from the disease in 2009. The 5-year survival rate for people diagnosed with pancreatic cancer is only five percent.

SOURCE Seattle Genetics, Inc.