Kosan Biosciences, Inc. (stock symbol: KOSN), was a pharmaceutical company which dealt with cancer therapeutics medications.

The company was working on advancing two new classes of anticancer agents through clinical development: heat shock protein 90 (Hsp90) inhibitors and epothilones.

Their technology platform was based on manipulation of the genetic instructions of microbes for making natural product polyketides.

[3] Discodermolide is a recently discovered polyketide natural product found to be a potent inhibitor of tumor cell growth.

Kosan had been working in conjunction with the Amos B. Smith research group on a preclinical drug development program.