Kosan Initiates Phase I Clinical Trial of Second-Generation Hsp90 Inhibitor KOS-1022

June 6, 2005

Kosan Biosciences has initiated a company-sponsored multicenter Phase I clinical trial of KOS-1022 (DMAG) in patients with advanced hematologic malignancies.

The Phase I clinical trial will assess the safety, pharmacokinetics and pharmacodynamics of escalating doses of KOS-1022 in patients with acute myelogenous leukemia, acute lymphocytic leukemia, or chronic myelogenous leukemia. According to the Phase I trial design, KOS-1022 will be given by one-hour infusion on a twice-weekly schedule every three weeks. In addition, the pharmacodynamics of KOS-1022 in leukemic blast cells will be investigated in order to determine the biological activity of KOS-1022 against client proteins critical to the progression of leukemia.

In addition to the Phase I study, KOS-1022 is being evaluated as a treatment for advanced solid tumors in Phase I clinical trials in advanced solid tumors sponsored by the National Cancer Institute.