8-K

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): February 3, 2006

OSCIENT PHARMACEUTICALS CORPORATION

(Exact name of registrant as specified in its charter)

Massachusetts	0-10824	04-2297484
(State or other jurisdiction of incorporation)	(Commission File Number)	(I.R.S. Employer Identification Number)

1000 Winter Street, Suite 2200

Waltham, Massachusetts 02451

(Address of principal executive offices, including zip code)

(781) 398-2300

(Registrant’s telephone number, including area code)

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 (see General Instruction A.2. below):

¨ 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.

1.    Sublicense and Distribution Agreement with Pfizer, S.A. de C.V.

On February 6, 2006, Oscient Pharmaceuticals Corporation (the “Company”) entered into a Sublicensing and Distribution Agreement with Pfizer, S.A. de C.V. (“Pfizer Mexico”) whereby the Company sublicensed its rights to sell FACTIVE^® (gemifloxacin mesylate) tablets in Mexico to Pfizer Mexico (“Pfizer Agreement”). Pfizer Mexico is responsible for obtaining regulatory approval for FACTIVE in Mexico. In exchange for those rights, Pfizer Mexico has agreed to pay the Company an up-front payment, milestones upon obtaining certain regulatory approvals and sales goals as well as royalties on future sales. These royalty rates are subject to reduction upon expiration of certain patents in Mexico for FACTIVE or if a generic form of gemifloxacin has a material impact on Pfizer Mexico’s sales volumes in Mexico.

Supply of Product

Pursuant to the Pfizer Agreement, Pfizer Mexico is obligated to exclusively purchase from the Company, and the Company must exclusively supply, all active pharmaceutical ingredient (“API”) for FACTIVE. The Company shall also initially provide Pfizer Mexico with bulk tablets in primary packaging until such time as Pfizer Mexico elects to transfer such fill-finish manufacturing to an alternate manufacturing source.

Termination

The Pfizer Agreement may be terminated by either party upon the occurrence of certain termination events, including Pfizer Mexico’s right to terminate at any time after the first anniversary of launch of FACTIVE tablets in Mexico upon six months prior written notice. Upon termination of the Pfizer Agreement, Pfizer Mexico is obligated to assign any and all rights to regulatory approvals in Mexico to the Company or its designee.

On February 7, 2006, the Company issued a press release announcing the entering into of the Pfizer Agreement. A copy of that press release is furnished with this Current Report on Form 8-K as Exhibit 99.1.

2.    Amendment to License and Option Agreement with LG Life Sciences Ltd.

Effective February 3, 2006, the Company amended its license and option agreement with LG Life Sciences, Ltd. for FACTIVE tablets. The amended agreement includes a reduction of future royalties payable to LG Life Sciences for sales of FACTIVE tablets in Mexico and Canada if the Company consummates sublicense agreements in such countries prior to dates specified in the amendment. The modified agreement also calls for additional milestone payments to be made to LG Life Sciences upon consummation of sublicense agreements in Mexico and Canada as well as upon receipt of regulatory approval of FACTIVE in each of such countries.

The foregoing is a summary description and, by its nature, is incomplete. All readers are encouraged to read the entire text of the Sublicensing and Distribution Agreement and Amendment to License and Option Agreement when they are filed. The Company’s filings may be accessed electronically by means of the SEC’s home page on the Internet at http://www.sec.gov or by means of the Company’s home page on the Internet at http://www.oscient.com under the heading “Investor Relations – SEC Filings.”

ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS.

(d) Exhibits

99.1    Press Release issued by Oscient Pharmaceuticals Corporation on February 7, 2006.

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.

OSCIENT PHARMACEUTICALS CORPORATION
By:	/S/    STEPHEN COHEN
	Name:  Stephen Cohen Title:    Senior Vice President and Chief Financial              Officer

Date:  February 7, 2006

EXHIBIT INDEX

Exhibit Number	Description
99.1	Press Release issued by Oscient Pharmaceuticals Corporation on February 7, 2006.

EX-99.1

Exhibit 99.1

Investor Contact:

Christopher Taylor

781-398-2466

Media Contact:

Sarah Emond

781-398-2544

For Immediate Release

Oscient Pharmaceuticals and Pfizer

Enter Agreement for FACTIVE Tablets in Mexico

— Pfizer, S.A. de C.V. to advance commercialization of

the fluoroquinolone antibiotic in Mexico —

Waltham, Mass., February 7, 2006 – Oscient Pharmaceuticals Corporation (Nasdaq: OSCI) has sublicensed the commercialization rights to FACTIVE^® (gemifloxacin mesylate) tablets in Mexico to Pfizer, S.A. de C.V. (Pfizer Mexico), the largest pharmaceutical company in that country. In exchange for those rights, Pfizer Mexico has agreed to pay Oscient an up-front payment, milestones for attaining certain regulatory and sales goals as well as royalties on future sales. Specific financial terms were not disclosed.

FACTIVE is currently approved in the U.S. for the treatment of community-acquired pneumonia of mild to moderate severity (CAP) and acute bacterial exacerbations of chronic bronchitis (AECB).

“FACTIVE represents an important addition to our antibiotic portfolio in Mexico,” stated Jorge Bracero, Regional President & General Manager, Northern Latin America, Pfizer. “We look forward to pursuing registration of this important antibiotic and making it available to local physicians and patients in Mexico dealing with often serious respiratory tract infections.”

“For us, this partnership with Pfizer in Mexico underscores the potential of FACTIVE,” stated Steven M. Rauscher, President and Chief Executive Officer of Oscient Pharmaceuticals. “Our business strategy, outside of the U.S., is to build the FACTIVE brand through partnerships with leading pharmaceutical companies in our licensed territories. This deal represents the first of similar agreements that we hope to establish in Canada and in certain European countries.”

Pfizer will work with the regulatory agency in Mexico to facilitate the marketing approval of FACTIVE. Oscient will be the sole provider of product to Pfizer Mexico.

About Pfizer Inc

Pfizer Inc discovers, develops, manufactures, and markets leading prescription medicines for humans and animals and many of the world’s best-known consumer brands. Our innovative, value-added products improve the quality of life of people around the world and help them enjoy longer, healthier, and more productive lives. The company has three business segments: health care, animal health and consumer health care. Our products are available in more than 150 countries.

About Oscient Pharmaceuticals

Oscient Pharmaceuticals Corporation is a biopharmaceutical company committed to the clinical development and commercialization of novel therapeutics to address unmet medical needs. The Company is marketing FACTIVE^® (gemifloxacin mesylate) tablets, approved by the FDA for the treatment of acute

bacterial exacerbations of chronic bronchitis and community-acquired pneumonia of mild to moderate severity. In addition to the oral tablet form, Oscient is developing an investigational FACTIVE intravenous formulation for use in hospitalized patients. The Company is also promoting Auxilium Pharmaceuticals’ TESTIM^® 1% testosterone gel to primary care physicians in the U.S. Oscient has a novel antibiotic candidate, Ramoplanin, in advanced clinical development for the treatment of Clostridium difficile-associated disease (CDAD).

Forward-Looking Statement for Oscient Pharmaceuticals

This press release may contain forward-looking statements, as defined by the Private Securities Litigation Reform Act of 1995, including statements regarding (i) the anticipated registration of FACTIVE tablets in Mexico, and (ii) our ability to establish partnerships in Canada and certain European countries. These statements represent, among other things, the expectations, beliefs, plans and objectives of management and/or assumptions underlying or judgments concerning matters discussed in this document. Forward-looking statements typically are identified by use of terms such as “may,” “will,” “should,” “plan,” “expect,” “intend,” “anticipate,” “estimate,” and similar words, although some forward-looking statements are expressed differently. We do not plan to update these forward-looking statements. You should be aware that our actual results could differ materially from those contained in the forward-looking statements due to a number of risks affecting our business. These risks include, but are not limited to, (i) the delay in or inability to obtain regulatory approvals of FACTIVE in other territories and (ii) our inability or our partners’ inability to successfully commercialize FACTIVE due to: the limitations on resources; lack of acceptance by physicians, patients and third party payors; unanticipated safety, product liability, efficacy, or other regulatory issues; delays in recruiting and training sales personnel; problems relating to manufacturing or supply; inadequate distribution of the products by wholesalers, pharmacies, hospitals and other customers; and competition from other products. Additional factors that could cause actual results to differ materially from those projected or suggested in any forward-looking statement are described under the heading “Factors Affecting Future Operating Results” in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in the Company’s Quarterly Report on Form 10-Q for the quarter ending September 30, 2005

#    #    #