•Item In5.01. connectionChanges within itsControl Selected Comparable Companies Analysis previously provided and described on page 97 of the joint proxy statement/prospectus, Lazard multiplied the aggregate six product candidates of the selected companies by the aggregate probability of success of such product candidates, and Lazard applied the range of technology values per expected product candidate derived from the selected companies to BioSante’s primary product candidateRegistrant.

SIGNATURE

EXHIBIT INDEX

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

~~WASHINGTON~~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~~ Report (Date of earliest event reported): ~~September~~October 1814, 2009

Cell Genesys, Inc.

(Exact name of registrant as specified in its charter)

Delaware	000-19986	94-3061375
(State or other jurisdiction of incorporation)	(Commission File Number)	(I.R.S. Employer Identification No.)
(State or Other Jurisdiction of Incorporation)	(Commission File Number)	(I.R.S. Employer Identification Number)

400 Oyster Point Boulevard, Suite 525, South San Francisco, California		94080
(Address of principal executive offices)		(Zip Code)
(Address of Principal Executive Offices)		(Zip Code)

~~Registrant’s telephone number, including area code:~~ (650) 266-3000

(Registrant’s telephone number, including area code)

Not Applicable

(Former name or former address, if changed since last report )

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:

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

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

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

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

Item 82.01. ~~Other~~Completion ~~Events~~of Acquisition or Disposition of Assets.

~~This~~On ~~Current~~October 14, ~~Report~~2009, onCell ~~Form~~Genesys, Inc. ~~8-K~~(“Cell isGenesys”) ~~being~~completed ~~filed~~its ~~pursuant~~previously toannounced ~~a memorandum of understanding regarding the settlement of certain litigation relating to the proposed~~ merger ~~(the~~with ~~“Merger”) between~~ BioSante Pharmaceuticals, Inc. (“BioSante”) ~~and Cell Genesys, Inc~~. ~~(“Cell~~Pursuant ~~Genesys”)~~to ~~pursuant~~the toterms ~~that~~of ~~certain~~an ~~Agreement~~agreement and ~~Plan~~plan of ~~Merger~~merger ~~(the “Merger Agreement”),~~ dated as of June 29, 2009, between BioSante and Cell Genesys. ~~This~~(the ~~communication~~“Merger ~~shall~~Agreement”), ~~not~~Cell ~~constitute~~Genesys merged anwith ~~offer~~and tointo ~~sell~~BioSante, orwith ~~the solicitation~~BioSante ofcontinuing anas ~~offer~~the tosurviving company ~~sell or~~ (the ~~solicitation~~“Merger”). The ofMerger Agreement anand ~~offer~~the totransactions ~~buy~~contemplated ~~any securities~~thereby, ~~nor~~including ~~shall~~the ~~there~~Merger, bewere approved ~~any~~by ~~sale~~the board of ~~securities~~directors inand ~~any~~stockholders ~~jurisdiction~~of ineach ~~which~~of ~~such~~BioSante ~~offer, solicitation or sale would be unlawful prior to registration or qualification~~and ~~under~~Cell ~~the~~Genesys. The ~~securities~~stockholders ~~laws~~ of BioSante ~~any~~and ~~such~~Cell ~~jurisdiction.~~Genesys Noapproved ~~offer~~the ofMerger ~~securities~~Agreement ~~shall~~and bethe ~~made~~transactions contemplated inthereby, ~~connection~~including ~~with~~ the Merger ~~except~~and, byin ~~means~~the case of the ~~definitive~~BioSante stockholders, ~~joint~~the ~~proxy~~issuance ~~statement/prospectus~~of shares of BioSante ~~and~~common ~~Cell~~stock ~~Genesys,~~in ~~dated~~the ~~August 24~~Merger, ~~2009,~~at ~~previously~~respective ~~mailed~~special tomeetings ~~shareholders~~ of ~~BioSante~~the ~~and~~stockholders ~~Cell~~held ~~Genesys and filed~~ on ~~August~~September 2430, 2009, ~~with~~in the ~~Securities~~case ~~and Exchange Commission as part~~ of athe ~~registration statement of~~ BioSante onspecial ~~Form~~meeting, ~~S-4~~and orOctober 14, as2009, in ~~otherwise~~the ~~pursuant~~case toof ~~applicable securities~~the ~~and~~Cell ~~any~~Genesys ~~other~~special ~~applicable laws~~meeting.

~~Settlement~~Subject to the terms and conditions of ~~Litigation~~the Merger Agreement, at the effective time of and as a result of the Merger, each share of common stock of Cell Genesys issued and outstanding immediately prior to the effective time of the Merger was converted into the right to receive 0.1828 of a share of BioSante common stock (the “Exchange Ratio”). No fractional shares of BioSante common stock were issued in connection with the Merger, and holders of Cell Genesys common stock are entitled to receive cash in lieu thereof.

AsIn ~~previously~~addition, ~~disclosed~~under onthe ~~page~~terms ~~108~~ of the ~~definitive~~Merger ~~joint proxy statement/prospectus~~Agreement, onall options ~~July 1,~~to ~~2009,~~purchase ashares ~~putative~~of ~~shareholder~~Cell ~~class~~Genesys ~~action~~common ~~lawsuit~~stock, ~~concerning~~other ~~the~~than ~~proposed~~certain designated ~~merger~~options ~~between~~held by Cell Genesys’s ~~and BioSante~~current ~~was~~officers ~~filed~~(the in“Specified Company ~~California~~Stock ~~Superior~~Options”), ~~Court~~became infully ~~San~~vested ~~Mateo~~and ~~County~~exercisable ~~(Case~~until ~~No. 485528)~~immediately prior ~~naming~~to ~~Cell~~the ~~Genesys,~~effective ~~its~~time ~~officers~~of ~~and~~the ~~directors, and BioSante as defendants~~Merger. On Upon ~~July 6,~~the ~~2009,~~effective atime ~~second~~of ~~putative~~the ~~shareholder~~Merger, ~~class~~such ~~action~~unexercised ~~lawsuit~~options other ~~naming~~than the ~~same~~Specified ~~parties~~Company ~~and~~Stock ~~containing~~Options ~~essentially~~terminated. The ~~identical~~Specified ~~allegations~~Company ~~was~~Stock ~~filed~~Options inwere assumed ~~California~~by ~~Superior~~BioSante ~~Court~~and inwill ~~San~~remain ~~Mateo~~outstanding ~~County~~following ~~(Case~~the ~~No. 485613). On July 8~~Merger, ~~2009,~~but converted ainto ~~third~~and ~~putative~~became ~~shareholder~~options ~~class~~to ~~action~~purchase ~~lawsuit~~shares ~~was~~of ~~filed~~BioSante incommon stock ~~California~~on ~~Superior~~terms ~~Court~~substantially identical to those in ~~San~~effect ~~Mateo~~prior ~~County~~to ~~(Case~~the ~~No. 485528)~~Merger, ~~which~~except for ~~also~~adjustments ~~named~~to the ~~same~~underlying ~~parties~~number ~~and~~of ~~contained~~shares ~~essentially~~and ~~identical~~the ~~allegations~~exercise asprice based on the ~~two~~Exchange ~~prior lawsuits~~Ratio. On All ~~July 15,~~warrants ~~2009,~~to purchase ~~the~~shares ~~Court~~of ~~consolidated~~Cell ~~these~~Genesys ~~three lawsuits~~common ~~into~~stock ~~one~~which ~~action~~by ~~and~~their ~~appointed~~terms ~~interim~~survived ~~lead~~the Merger ~~counsel. On~~were ~~August 13,~~assumed ~~2009~~by BioSante, ~~plaintiffs~~but ~~filed~~were aconverted ~~Consolidated~~into ~~Class Action~~and ~~Complaint~~became ~~alleging~~warrants ~~that~~to purchase ~~defendants~~shares ~~breached~~of ~~their~~BioSante ~~fiduciary~~common ~~duties~~stock ~~and/or~~on ~~aided~~terms ~~and~~substantially ~~abetted~~identical ~~the breach of~~to ~~fiduciary~~those ~~duties~~in ~~owed~~effect prior to ~~Cell~~the ~~Genesys~~Merger, ~~stockholders~~except infor ~~connection~~adjustments ~~with~~to the ~~proposed~~underlying number ~~merger,~~of ~~including~~shares byand ~~failing~~the toexercise ~~engage~~price inbased aon ~~fair~~the ~~sales~~Exchange ~~process~~Ratio. In addition, ~~failing~~as ~~to obtain~~ a ~~fair~~result ~~price~~of ~~for~~ the ~~sale~~Merger, BioSante ofassumed ~~Cell~~$1.2 ~~Genesys,~~million ~~and~~in ~~failing~~principal toamount ~~provide~~of ~~Cell~~3.125% ~~Genesys~~convertible senior ~~stockholders~~notes ~~with~~due ~~material~~in ~~information~~November 2011 ~~regarding~~and ~~the~~$20.8 ~~proposed~~million ~~merger. Plaintiffs~~in ~~seek~~principal anamount ~~order~~of ~~certifying~~3.125% convertible ~~the~~senior ~~lawsuit~~notes asdue ain ~~class~~May 2013 ~~action,~~issued ~~injunctive~~by ~~relief~~Cell toGenesys, ~~enjoin~~and ~~the~~such notes ~~merger~~became ~~or,~~convertible ininto ~~the~~shares ~~event~~of ~~the~~BioSante ~~merger~~common isstock ~~completed,~~as a ~~rescission~~result of the merger or ~~rescissory~~in ~~damages. Plaintiffs~~accordance ~~further~~with ~~seek~~the anterms ~~accounting~~of ~~for~~the ~~all~~indentures ~~damages~~governing ~~and~~such annotes as ~~award~~supplemented ofby ~~attorneys’~~supplemental ~~fees~~indentures entered in to between BioSante and the ~~costs.~~trustees thereunder.

~~Solely~~In tothe ~~avoid~~aggregate, ~~the~~BioSante issued approximately 20.2 million ~~costs,~~shares ~~risks~~of ~~and~~its ~~uncertainties~~common ~~inherent~~stock into ~~litigation,~~former Cell Genesys ~~and~~stockholders ~~the~~in ~~other~~connection with ~~defendants~~the ~~have~~Merger. The ~~entered~~issuance ~~into~~of BioSante acommon ~~memorandum~~stock ofto ~~understanding~~the ~~with~~Cell ~~plaintiffs’~~Genesys ~~counsel~~stockholders in ~~the~~connection ~~San~~with ~~Mateo~~the Merger ~~County~~was ~~action~~registered (under the ~~“Memorandum~~Securities Act of ~~Understanding”)~~ 1933, as amended, pursuant to a ~~which~~registration ~~Cell~~statement ~~Genesys,~~on ~~the~~Form S-4 ~~other~~(File ~~named~~No. 333-161181), ~~defendants~~initially filed ~~and~~by BioSante with the ~~plaintiffs~~Securities ~~have~~and ~~agreed~~Exchange toCommission ~~settle~~on ~~the~~August 7, 2009 ~~lawsuits~~and ~~subject~~declared toeffective ~~court~~on ~~approval~~August 21, 2009. IfBioSante’s ~~the~~Form S-4 registration ~~court~~statement, ~~approves~~including the ~~settlement~~joint proxy statement/prospectus included therein, ~~the~~contains ~~lawsuits~~additional ~~will~~information beabout ~~dismissed~~the ~~with~~Merger ~~prejudice.~~and the related transactions.

~~Pursuant~~Item to3.01. ~~the~~Notice ~~Memorandum~~ of ~~Understanding,~~Delisting ~~Cell~~or ~~Genesys~~Failure ~~has agreed~~ to ~~pay~~Satisfy to plaintiffs’ counsel an amount not more than $240,000 as is approved by court order for plaintiffs’ attorneys’ fees, costs and expenses in the San Mateo County action and to make the following additional disclosures in a ~~Form~~Continued ~~8-K,~~Listing ~~without~~Rule ~~admitting in any way that the disclosures below are material~~ or ~~otherwise~~Standard; ~~required by~~Transfer ~~law:~~of Listing.

•(d) Following completion ~~Cell~~of ~~Genesys~~the ~~retained~~Merger aon ~~financial~~October 14, ~~advisor~~2009, inCell ~~connection~~Genesys ~~with~~notified the NASDAQ ~~merger,~~Global ~~Lazard~~Market ~~Freres~~that &the ~~Co.~~Merger ~~LLC~~had ~~(“Lazard”).~~been ~~Cell~~completed ~~Genesys~~and ~~retained~~that ~~Lazard~~as ~~due~~a toresult ~~Lazard’s~~of the ~~reputation~~merger, ~~and~~each ~~experience~~outstanding ~~advising~~share ~~companies~~of inCell ~~similar~~Genesys ~~circumstances,~~common asstock ~~described~~was inconverted into ~~more~~the ~~detail~~right into receive the ~~definitive~~merger ~~joint proxy statement/prospectus.~~

• Cell Genesys management identified more than 100 potential public and private counterparties, as previously disclosed on page 68 of the definitive joint proxy statement/prospectus. The criteria developed Cell Genesys management to identify such potential counterparties included, among other things, possession of existing product candidates compatible with Cell Genesys’s existing product candidates and proprietary technology, and a likely desire to pursue a transaction with Cell Genesys. All such potential counterparties identified by Cell Genesys were strategic buyers.2

•consideration, as Ondescribed ~~December~~above ~~19,~~under ~~2008,~~the asheading ~~previously~~“Item ~~disclosed~~2.01. onCompletion ~~page~~of 71Acquisition or Disposition of Assets.” Cell Genesys requested that NASDAQ file with the ~~definitive~~Securities ~~joint~~and ~~proxy~~Exchange ~~statement/prospectus,~~Commission ~~Lazard~~an application ~~sent~~on ~~letters~~Form 25 to ~~potential~~strike ~~counterparties,~~Cell ~~public~~Genesys common stock from listing on NASDAQ and ~~private,~~from ~~requesting~~registration anunder ~~indication~~Section 12(b) of the Securities Exchange Act of ~~interest~~1934, as amended (the “Exchange Act”). Cell OnGenesys ~~such~~intends ~~date,~~to ~~Lazard~~file ~~sent~~a ~~letters~~certification on Form 15 to ~~nine~~terminate ~~such~~the ~~potential~~registration ~~counterparties,~~of ~~based~~its oncommon stock under Section 12(g) of the ~~criteria~~Exchange ~~developed~~Act by(and ~~Cell~~its ~~Genesys~~corresponding ~~management~~reporting ~~described~~obligation ~~above~~under Section 13(a) of the Exchange Act) and to suspend its reporting obligations under Section 15(d) of the Exchange Act.

•Item ~~Cell~~3.03. ~~Genesys’s~~Material ~~management~~Modification ~~developed internal estimates as~~ to ~~the~~Rights ~~potential market value~~ of ~~Cell~~Security ~~Genesys’s assets, as previously disclosed on page 97 of the joint proxy statement/prospectus~~Holders. ~~Such internal estimates ranged from $34.7 million to $45 million (including cash).~~

•Pursuant to ~~Lazard~~the ~~reviewed~~Merger Agreement, ~~among~~each ~~other~~outstanding ~~things,~~share ~~technology~~of ~~values~~Cell ~~per~~Genesys ~~expected~~common ~~product~~stock issued ~~candidate~~and ofoutstanding ~~certain~~prior ~~companies~~to asthe ~~part~~effective time of ~~its~~the ~~Selected~~Merger ~~Comparable~~was ~~Companies~~converted into ~~Analysis,~~the asright ~~previously~~to ~~disclosed~~receive onthe ~~page~~merger 97consideration, ofas described above under the ~~joint~~heading ~~proxy~~“Item ~~statement/prospectus~~2.01. ~~This~~Completion isof aAcquisition ~~method~~or ~~used~~Disposition byof ~~Lazard~~Assets,” which todescription ~~evaluate~~is ~~early~~incorporated ~~stage~~by ~~biotechnology~~reference ~~companies~~herein.

Upon the closing of the Merger on October 14, 2009, a change in control of Cell Genesys ~~does~~occurred. ~~not~~Pursuant ~~believe~~to ~~that~~the terms of the ~~additional~~Merger ~~disclosures~~Agreement, ~~above~~Cell ~~are material~~Genesys merged with and into BioSante, ~~were~~with ~~required~~BioSante continuing toas bethe ~~included~~surviving incompany, as described above under the ~~joint~~heading ~~proxy~~“Item 2.01. ~~statement/prospectus~~Completion of Acquisition or ~~are~~Disposition ~~otherwise~~of ~~required~~Assets,” which description is incorporated by ~~law,~~reference orherein. In ~~that~~the aggregate, ~~they~~BioSante ~~provide~~issued ~~substantively~~approximately ~~new~~20.2 ormillion ~~different~~shares ~~information~~of ~~compared~~its common stock to ~~the~~former ~~information~~Cell ~~already~~Genesys ~~provided~~stockholders in connection with the ~~definitive~~Merger. As ~~joint~~a result ~~proxy~~of ~~statement/prospectus.~~the ~~Such~~Merger, ~~disclosures~~the ~~are~~stockholders ~~being~~of ~~provided~~BioSante ~~solely~~prior to ~~avoid~~the Merger own approximately 62 percent of the ~~costs,~~outstanding ~~risks~~common stock of the combined company and ~~uncertainties~~the ~~inherent~~former inCell Genesys stockholders own approximately 38 percent of the ~~litigation~~outstanding ~~mentioned~~common ~~above.~~stock of the combined company.

~~Important~~Pursuant ~~Additional~~to ~~Information~~the ~~for~~terms ~~Investors~~of the Merger Agreement and ~~Stockholders~~as a result of and by virtue of the Merger, Stephen A. Sherwin, M.D. and John T. Potts, Jr., M.D., both former directors of Cell Genesys, joined the board of directors of BioSante at the effective time of the Merger.

~~This~~Item ~~communication~~5.02 isDeparture ~~being made in respect~~ of ~~the~~Directors ~~proposed~~or ~~business combination~~Certain ~~involving~~Officers; ~~BioSante~~Election ~~and~~of ~~Cell~~Directors; ~~Genesys.~~Appointment In connection with the proposed transaction, BioSante has filed with the SEC, a registration statement on Form S-4, containing a joint proxy statement/prospectus and other relevant materials. The final joint proxy statement/prospectus has been mailed to the stockholders of ~~record~~Certain asOfficers; ofCompensatory ~~August 21,~~Arrangements ~~2009,~~ of ~~BioSante~~Certain ~~and Cell Genesys~~Officers. INVESTORS AND SECURITY HOLDERS OF BIOSANTE AND CELL GENESYS ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS (INCLUDING ANY AMENDMENTS OR SUPPLEMENTS) AND OTHER DOCUMENTS FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY BECAUSE THEY CONTAIN IMPORTANT INFORMATION ABOUT BIOSANTE, CELL GENESYS AND THE PROPOSED TRANSACTION.

~~Investors~~(b) Pursuant ~~and security holders are able~~ to ~~obtain~~the ~~free~~terms ~~copies~~ of the ~~registration~~Merger ~~statement~~Agreement, ~~and~~David ~~the~~W. ~~joint~~Carter, ~~proxy~~Nancy ~~statement/prospectus and other documents filed with the~~M. ~~SEC~~Crowell, byJames ~~BioSante~~M. ~~and~~Gower, ~~Cell~~Thomas ~~Genesys~~E. atShenk, ~~the SEC’s web site at www~~Ph.~~sec~~D.~~gov. Free copies of the registration statement and the joint proxy statement/prospectus and other documents filed with the SEC can also be obtained by directing a request to BioSante~~, ~~Attention:~~Eugene ~~Investor~~L. ~~Relations~~Step, ~~telephone:~~Inder ~~(847) 478-0500~~M. ~~or to Cell Genesys~~Verma, ~~Attention: Investor Relations~~ Ph.~~, telephone (650) 266-3200~~D. ~~In addition, investors~~ and ~~security~~Dennis ~~holders~~L. ~~may~~Winger, ~~access~~former ~~copies~~members of the ~~documents~~Cell ~~filed~~Genesys ~~with~~board ~~the~~of ~~SEC by BioSante on BioSante’s website at www.biosantepharma.com~~directors, ~~and~~resigned ~~investors~~immediately ~~and~~prior ~~security~~to ~~holders~~the ~~may~~completion ~~access copies~~ of the ~~documents filed with the SEC by Cell Genesys’s website at www~~Merger.~~cellgenesys.com.~~

~~BioSante,~~Immediately ~~Cell~~after ~~Genesys~~the ~~and~~completion ~~their~~of ~~respective~~the ~~directors~~Merger, BioSante ~~and~~terminated ~~executive~~the ~~officers~~employment ~~and~~of ~~other~~each ~~persons~~of ~~may~~Stephen beA. ~~deemed~~Sherwin, toM.D., bethe former ~~participants~~chairman inof the ~~solicitation~~board ofand ~~proxies~~chief ~~from~~executive ~~the stockholders~~officer of ~~BioSante and~~ Cell Genesys, Sharon inE. ~~respect~~Tetlow, of the ~~proposed~~former ~~transaction.~~senior ~~Information~~vice ~~regarding~~president ~~BioSante’s directors~~ and ~~executive~~chief ~~officers~~financial isofficer of ~~available~~Cell inGenesys, ~~its~~Marc ~~annual~~L. ~~report~~Belsky, ~~on Form 10-K for~~ the ~~year~~former ~~ended~~vice ~~December 31~~president, ~~2008,~~finance ~~filed~~and chief ~~with~~accounting ~~the~~officer ~~SEC~~of onCell ~~March 16~~Genesys, ~~2009~~ and ~~the~~Robert ~~proxy~~H. ~~statement~~Tidwell, ~~for~~the ~~BioSante’s~~former ~~2009~~senior vice ~~annual meeting of stockholders~~president, ~~filed~~corporate ~~with~~development ~~the~~of ~~SEC~~Cell ~~on April 27~~Genesys, ~~2009.~~effective immediately.

~~Information~~Item regarding Cell Genesys’s directors and executive officers is available in its annual report on Form 10-K for the year ended December 31, 2008, filed with the SEC on March 9, 2009 and the proxy statement for Cell Genesys’s 2009 annual meeting of stockholders, filed with the SEC on March 31, 20097.01 ~~Investors~~Regulation ~~and~~FD stockholders can obtain more detailed information regarding the direct and indirect interests of BioSante’s and Cell Genesys’s directors and executive officers in the merger by reading the definitive joint proxy statement/prospectusDisclosure.

~~Forward~~On October 14, 2009, Cell Genesys issued a news release announcing the completion of the Merger. A copy of the news release is furnished as Exhibit 99.1 to this Current Report on Form 8-~~Looking~~K ~~Statements~~and is incorporated herein by reference.

~~This~~The ~~communication~~information ~~contains~~contained forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 about BioSante and Cell Genesys. Such statements include, but are not limited to, statements about the proposed transaction and its potential benefits to the BioSante and Cell Genesys stockholders, the expected timing of the completion of the transaction, the combined company’s plans, objectives, expectations and intentions with respect to future operations and products and other statements that are not historical in ~~nature,~~this ~~particularly~~Item those that utilize terminology such as “will,” “potential,” “could,” “can,” “believe,” “intends,” “continue,” “plans,” “expects,” “estimates” or comparable terminology7.01 ~~Forward-looking statements are based on current expectations~~ and ~~assumptions, and entail various known and unknown risks and uncertainties that could cause actual results to differ materially from those expressed in such forward-looking statements~~Exhibit 99. ~~Important factors known to BioSante and Cell Genesys that~~1 ~~could cause actual results~~ to ~~differ~~this ~~materially~~report ~~from~~shall those expressed in such forward-looking statements include general business and economic conditions; the failure of the BioSante or Cell Genesys stockholders to approve the transaction or the failure of either party to meet any of the other conditions to the closing of the transaction; the failure to realize the anticipated benefits from the transaction or delay in realization thereof; the businesses of BioSante and Cell Genesys may not be ~~combined successfully, or such combination may take longer,~~ be ~~more~~deemed ~~difficult, time-consuming or costly~~ to accomplish than expected; and operating costs and business disruption following the merger, including adverse effects on employee retention and on business relationships with third parties, BioSante’s need for and ability to obtain additional financing, the difficulty of developing pharmaceutical products, obtaining regulatory and other approvals and achieving market acceptance; the marketing success of BioSante’s licensees or sublicensees and the success of clinical testing. Additional factors that could cause BioSante’s and Cell Genesys’s results to differ materially from those described in the forward-looking statements can be found in BioSante’s recent registration statement on Form S-4 and BioSante’s and Cell Genesys’s most recent annual reports on Form 10-K and subsequent quarterly reports on Form 10-Q and other filings with the

Securities and Exchange Commission, which are filed with the SEC and available at the SEC’s web site at www.sec.gov and which discussions also are incorporated herein by reference. The information set forth herein speaks only as of the date hereof, and BioSante and Cell Genesys disclaim any intention and do not assume any obligation to update or revise any forward looking statement, whether as a result of new information, future events or otherwise. 3

~~SIGNATURES~~“filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liability of that section, and shall not be incorporated by reference into any filings made by Cell Genesys under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended, except as may be expressly set forth by specific reference in such filing.

~~Pursuant~~Item to9.01. ~~the~~Financial ~~requirements~~Statements ofand ~~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~~Exhibits.

(d) Exhibits.

Exhibit No.	Description	Method of Filing
2.1	Agreement and Plan of Merger dated as of June 29, 2009 by and between BioSante Pharmaceuticals, Inc. and Cell Genesys, Inc.*	Incorporated by reference to Exhibit 2.1 to Cell Genesys’s Current Report on Form 8-K filed with the Securities and Exchange Commission on June 30, 2009
99.1	News release issued by Cell Genesys, Inc. on October 14, 2009	Furnished herewith

* All exhibits and schedules to this exhibit have been omitted pursuant to Item 601(b)(2) of Regulation S-K. Cell Genesys will furnish the omitted exhibits and schedules to the Securities and Exchange Commission upon request by the Securities and Exchange Commission.

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.

		CELL GENESYS, INC.

	By:	/s/ Phillip B. Donenberg
		Phillip B. Donenberg, Chief Financial Officer, Treasurer and Secretary of BioSante Pharmaceuticals, Inc., successor in interest to Cell Genesys, Inc. and Authorized Person

Date: October 14, 2009

CELL GENESYS, INC.

CURRENT REPORT ON FORM 8-K

Cell Genesys, Inc.

September 18, 2009

/s/ Sharon E. Tetlow

Sharon E. Tetlow

Senior Vice President and Chief Financial Officer

Exhibit No.	Description	Method of Filing
2.1	Agreement and Plan of Merger dated as of June 29, 2009 by and between BioSante Pharmaceuticals, Inc. and Cell Genesys, Inc.*	Incorporated by reference to Exhibit 2.1 to Cell Genesys’s Current Report on Form 8-K filed with the Securities and Exchange Commission on June 30, 2009
99.1	News release issued by Cell Genesys, Inc. on October 14, 2009	Furnished herewith

Filing Compare · CELL GENESYS INC