Kosan Initiates Phase 2 Trial of Alvespimycin, Second-Generation Hsp90 Inhibitor, in HER2-Positive Metastatic Bre...( HAYWARD Calif. Jan. 15 /- Kosan B...),Health

HAYWARD, Calif., Jan. 15 /PRNewswire-FirstCall/ -- Kosan Biosciences Incorporated (Nasdaq: KOSN) today announced the initiation of a Phase 2 trial of alvespimycin, the company's second-generation Hsp90 inhibitor, in patients with HER2-positive metastatic breast cancer. Alvespimycin has demonstrated the potential to disrupt the activity of multiple oncogenes and cell signaling pathways implicated in tumor growth, including HER2, a key signaling pathway in breast cancer. The objective of the Phase 2 trial is to evaluate the safety and anticancer activity of alvespimycin as a single agent in patients who have not previously received Herceptin for metastatic disease except in an adjuvant setting. Antitumor data in patients with advanced HER2-positive cancer presented at the September 2007 American Society of Oncology (ASCO) Breast Cancer Symposium demonstrated encouraging antitumor activity of alvespimycin in combination with trastuzumab (Herceptin(R)).

"HER2-positive metastatic breast cancer represents a major market opportunity for Kosan that we intend to pursue," said Robert G. Johnson, Jr., M.D., Ph.D., Kosan's President and Chief Executive Officer. "We believe that emerging safety and efficacy data from our clinical trials in this indication with both of our Hsp90 inhibitors and the demonstrated activity in refractory disease represent a meaningful therapeutic opportunity. We believe that characterization of the single-agent activity of an Hsp90 inhibitor in HER2-positive metastatic breast cancer will provide valuable information to support the design of later-stage trials."

Alvespimycin Phase 2 Development Plan

The single-agent trial of alvespimycin will be conducted in Eastern Europe and will recruit up to 30 patie
'/>"/>