8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D) OF

THE SECURITIES EXCHANGE ACT OF 1934

DATE OF REPORT (DATE OF EARLIEST EVENT REPORTED):

AUGUST 13, 2004

KOSAN BIOSCIENCES INCORPORATED

(Exact name of registrant specified in its charter)

DELAWARE	000-31633	94-3217016
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

3832 BAY CENTER PLACE HAYWARD, CA 94545

(Address of principal executive offices) (Zip Code)

REGISTRANT’S TELEPHONE, INCLUDING AREA CODE: (510) 732-8400

Item 5. OTHER EVENTS AND REGULATION FD DISCLOSURE

On Friday August 13, 2004, Kosan Biosciences Incorporated (the “Company”) announced via a press release changes to its senior management team. A copy of the Company’s press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

The information in this Report on Form 8-K, including the exhibit hereto, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section or Sections 11 and 12(a)(2) of the Securities Act of 1933, as amended. The information contained herein and in the accompanying exhibit shall not be incorporated by reference into any filing with the U.S. Securities and Exchange Commission by the Company, whether made before or after the date hereof, regardless of any general incorporation language in such filing.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

KOSAN BIOSCIENCES INCORPORATED
(Registrant)
By	/s/ Daniel V. Santi
	Daniel V. Santi, M.D., Ph.D.
	Chairman and Chief Executive Officer

Dated: August 13, 2004

EXHIBIT INDEX

Exhibit	Description
99.1	Press Release dated August 13, 2004, relating to the Company’s senior management changes.

EX-99.1

Exhibit 99.1

Contacts:
Kosan Biosciences
Susan M. Kanaya	Shari Annes
Chief Financial Officer	(650) 888-0902 (cell)
(510) 732-8400, ext. 5227	(510) 731-5260
kanaya@kosan.com	annes@kosan.com
FOR IMMEDIATE RELEASE

KOSAN ANNOUNCES SENIOR MANAGEMENT CHANGES

Hayward, CA – August 13, 2004 – Kosan Biosciences Incorporated (Nasdaq: KOSN) announced today changes to its senior management team. Michael S. Ostrach, President and Chief Operating Officer, has resigned from these positions and will become a consultant to the Company; Robert G. Johnson, Jr., M.D., Ph.D., has been promoted to Executive Vice President, Development and Chief Medical Officer; and Gary Palmer, M.D, has joined the Company as Executive Director, Medical Affairs.

According to Daniel V. Santi, M.D., Ph.D., Chairman and Chief Executive Officer, “The changes at Kosan underscore the Company’s expanded clinical development activities and the advancement of key research programs into the clinical arena.

“Since 1997 when Michael joined Kosan, he has been instrumental in building the leadership team and guiding the Company’s evolution from its early stage platforms to its current product orientation. From business development and financing, as well as operational and legal perspectives, his contributions have provided a foundation for Kosan’s leadership in developing polyketide products. We look forward to Michael’s continued contributions,” added Dr. Santi.

Robert G. Johnson, Jr., M.D., Ph.D., formerly Senior Vice President, Medical Affairs and Chief Medical Officer, is responsible for Kosan’s preclinical, clinical, and pharmacology groups. His promotion reflects his substantial contributions to Kosan’s clinical programs and his ongoing critical role in Kosan’s continued success. Dr. Johnson formerly worked with Merck and Chiron.

Gary Palmer, M.D. joins Kosan from Salmedix in San Diego, where he was Medical Director for Clinical Development. Prior to that, he was Associate Medical Director at Amgen. Dr. Palmer has led or participated in the filings of multiple INDs as well as NDAs. He is also a medical oncologist with over 15 years of patient experience.

About Kosan

Kosan Biosciences has two first-in-class anticancer agents in Phase II clinical trials. KOS-862 (Epothilone D) is in Phase II and Phase Ib clinical trials and is partnered with Roche in a global development and commercialization agreement. 17-AAG, Kosan’s lead geldanamycin analog, is in Phase II and Phase Ib clinical trials, and DMAG, its second-generation geldanamycin analog, is in Phase I. Both compounds are being developed in collaboration with the National Cancer Institute. Kosan’s proprietary formulation of 17-AAG, designated KOS-953, is in Phase I. KOS-953, 17-AAG and DMAG are polyketide inhibitors of Hsp90 and interrupt several biological processes implicated in cancer cell growth and survival. Kosan’s focus is on an important class of natural products known as polyketides. Polyketides are a class of natural products that have yielded numerous important pharmaceuticals for the treatment of cancer, infectious diseases, high cholesterol, transplant rejection and other diseases. Kosan applies its expertise and proprietary technologies to generate polyketide analogs and increase the production yields of polyketides, resulting in a robust pipeline of potentially significant products for cancer, as well as for infectious disease and other therapeutic areas. For additional information on Kosan Biosciences, please visit the Company’s website at www.kosan.com.

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