On May 9, 2008, Cell Genesys, Inc. (the “Company”) entered into a Placement Agency Agreement with Credit Suisse Securities (USA) LLC, Canaccord Adams Inc. and Cantor Fitzgerald & Co. relating to the issuance and sale by the Company of 7,109,005 shares of the Company’s common stock, and warrants to purchase 8,530,806 shares of the Company’s common stock to the institutional investor signatories to the Subscription Agreement described below. The warrants have an exercise price of $10 per share. Each purchaser of a share of common stock purchased a warrant exercisable for 1.2 shares of the Company’s common stock, for a collective price of $4.22 per share and warrant unit, which the Company estimates will result in net proceeds of approximately $28.0 million, after deducting the placement agents’ fees and estimated offering expenses. The warrants will not be exercisable prior to six months after issuance, and will be exercisable for a period of seven years thereafter. A copy of the Placement Agency Agreement is attached hereto as Exhibit 1.1 to this report and is incorporated herein by reference. A copy of the form of warrant is attached hereto as Exhibit 4.1 to this report and is incorporated herein by reference. The description of the warrants is a summary only and is qualified in its entirety by reference to Exhibit 4.1.

In connection with the offering, the Company entered into a subscription agreement, dated May 9, 2008 (the “Subscription Agreements”), between the Company and the investors. The form of Subscription Agreement is attached hereto as Exhibit 10.1 to this report and is incorporated herein by reference.

Credit Suisse Securities (USA) LLC acted as lead placement agent and Canaccord Adams Inc. and Cantor Fitzgerald & Co. acted as co-placement agents for the offering and will receive placement fees equal to 5% of the aggregate purchase price of approximately $1.5 million from the offering.

The Company is making the issuance and sale pursuant to a shelf registration statement on Form S-3 (Registration No. 333-142482) declared effective by the Securities and Exchange Commission on May 16, 2007.

On May 12, 2008, the Company issued a press release announcing the public offering referred to above. A copy of the press release is attached hereto as Exhibit 99.1 and hereby incorporated by reference.

The information in this Current Report on Form 8-K under the heading Item 7.01, “Regulation FD Disclosure,” including Exhibit 99.1, is being furnished and shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act unless specifically stated in those filings.

(c) Exhibits.

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.

Exhibit Index