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): July 20, 2006

Kosan Biosciences Incorporated

(Exact name of registrant as specified in its charter)

Delaware

(State or other jurisdiction of incorporation)

000-31633	94-3217016
(Commission File Number)	(IRS Employer Identification No.)

3832 Bay Center Place, Hayward, CA 94545

(Address of principal executive offices, including Zip Code)

Registrant’s telephone number, including area code: (510) 732-8400

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

¨ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

¨ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

¨ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

¨ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 1.01 Entry into a Material Definitive Agreement.

On July 20, 2006, the Compensation Committee of the Board of Directors (the “Board”) of Kosan Biosciences Incorporated (the “Company”), increased the annual base salary of Peter J. Licari, Ph.D., Senior Vice President, Manufacturing and Operations, to $245,000, effective July 1, 2006 and approved a $25,000 cash bonus payment to Margaret A. Horn, Senior Vice President, Legal and Corporate Development, General Counsel and Secretary.

Item 5.02 Departure of Directors or Principal Officers; Election of Officers; Appointment of Officers.

On July 20, 2006, the Board appointed Robert G. Johnson, Jr., M.D., Ph.D., the Company’s Chief Executive Officer, as a member of the Board. Dr. Johnson will serve as a Class C director, having a term of office expiring at the 2009 Annual Meeting of Stockholders of the Company. Dr. Johnson is not expected to be named to any committees of the Board. In connection with Dr. Johnson’s appointment, the Board increased the number of authorized directors to eight.

On July 26, 2006, Kosan issued a press release announcing the appointment of Dr. Johnson to the Board. A copy of the press release is filed as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference herein.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

Number	Description
99.1	Press Release entitled “Kosan Appoints CEO Robert Johnson to Board of Directors.”

SIGNATURES

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
Dated: July 26, 2006	By:	/s/ Margaret A. Horn
		Margaret A. Horn,
		Senior Vice President, Legal and Corporate Development, General Counsel and Secretary

EXHIBIT INDEX

Number	Description
99.1	Press Release entitled “Kosan Appoints CEO Robert Johnson to Board of Directors.”

EX-99.1

Exhibit 99.1

Contact:

Kosan Biosciences

Jane Green

510.731.5335 (office)

510.652.4819 (mobile)

green@kosan.com

FOR IMMEDIATE RELEASE

KOSAN APPOINTS CEO ROBERT JOHNSON TO BOARD OF DIRECTORS

Hayward, CA – July 26, 2006 – Kosan Biosciences Incorporated (Nasdaq:KOSN) announced that Robert G. Johnson, Jr., M.D., Ph.D., Kosan’s Chief Executive Officer, has been appointed to the Company’s Board of Directors.

“Robert has brought leadership, direction and energy to the management of Kosan’s overall business, built a reputation for integrity and openness within the investment community, and infused the management team and employees with a strong sense of motivation and purpose,” said Peter Davis, Ph.D., Kosan’s Chairman of the Board of Directors. “Today, Kosan is operating with a high degree of productivity, effectiveness and fiscal responsibility. The Board of Directors joins me in expressing confidence in Robert’s management and the additional value he will bring to the Company as a Board member.”

Dr. Johnson has served as Kosan’s Chief Executive Officer since April 2006, having been named Acting Chief Executive Officer in February 2006. From April 2004 to February 2006, Dr. Johnson was Executive Vice President, Development, and Chief Medical Officer. From January 2002 to April 2004, Dr. Johnson served as Senior Vice President, Medical Affairs and Corporate Development, and in January 2003, he was also named Kosan’s Chief Medical Officer. From September 2000 to January 2002, Dr. Johnson served as Vice President, Medical Affairs and Corporate Development. From 1998 to September 2000, Dr. Johnson was employed by Chiron Corporation, where he served as Vice President, Pharmacology and Preclinical Affairs through 1999 and as Vice President, Corporate Development. From 1991 to 1998, Dr. Johnson was Director of Pharmacology at Merck & Co., Inc. In addition, Dr. Johnson was a member of the faculty at the University of Pennsylvania from 1987 to 1991 and at Harvard Medical School from 1985 to 1987. Dr. Johnson received a B.A. and a Ph.D. in biophysics and an M.D. from the University of Pennsylvania.

About Kosan

Kosan Biosciences is a biotechnology company advancing two new classes of anticancer agents through clinical development – Hsp90 (heat shock protein 90) inhibitors and epothilones. Kosan is leveraging its proprietary discovery platform to generate a pipeline of potentially significant product candidates, primarily in the area of oncology.

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Hsp90 inhibitors have a novel mechanism of action targeting multiple pathways involved in cancer cell growth and survival. KOS-953 is Kosan’s proprietary formulation of 17-AAG, a geldanamycin analog. The agent is currently in Phase I and II clinical trials, primarily for multiple myeloma andHER2-positive breast cancer. In addition, intravenous and oral formulations of Kosan’s second-generation Hsp90 inhibitor, KOS-1022, are being evaluated in Phase I clinical trials.

Epothilones inhibit cell division with a mechanism of action similar to taxanes, one of the most successful classes of anti-tumor agents. KOS-862 is currently being studied in a Phase II single-agent clinical trial in patients with metastatic breast cancer, as well as a Phase II combination trial with Herceptin. KOS-1584, a second candidate designed to improve pharmacokinetics, is in Phase I clinical trials in patients with solid tumors. Kosan’s epothilone program is partnered with Roche through a global development and commercialization agreement.

For additional information on Kosan Biosciences, please visit the company’s website at www.kosan.com.

This press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995 (the “Act”). Any statements contained in this press release that are not statements of historical fact may be deemed to be forward-looking statements. There are a number of important factors that could cause the results of Kosan to differ materially from those indicated by these forward-looking statements, including, among others, risks related to the clinical advancement of Kosan’s clinical candidates, including the risk that clinical trials may not demonstrate safety and efficacy sufficient to obtain the requisite regulatory approvals or to result in a marketable product; and other risks detailed from time to time in the Company’s SEC reports, including its Quarterly Report on Form 10-Q for the quarter ended March 31, 2006 and other periodic filings with the SEC. Kosan does not undertake any obligation to update forward-looking statements.

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