VICURON PHARMACEUTICALS INC. AND OSCIENT PHARMACEUTICALS CORPORATION ASSIGNMENT AND TERMINATION AGREEMENT

Exhibit 10.3

VICURON PHARMACEUTICALS INC.

AND

OSCIENT PHARMACEUTICALS CORPORATION

ASSIGNMENT AND TERMINATION AGREEMENT

THIS ASSIGNMENT AND TERMINATION AGREEMENT (the “Agreement”) is made effective as of the 3 ^RD day of February, 2006 (the “Effective Date”) by and between Oscient Pharmaceuticals Corporation (formerly known as Genome Therapeutics Corporation), a Massachusetts corporation having its principal place of business at 1000 Winter Street, Suite 2200, Waltham, MA 02451, USA (“Oscient”) and Vicuron Pharmaceuticals Inc., a Delaware corporation with its principal place of business at 455 South Gulph Road, Suite 305, King of Prussia, PA 19406, USA (for itself and as successor-in-interest to Biosearch Italia, “Vicuron”). Oscient and Vicuron are sometimes referred to herein individually as a “Party” and collectively as the “Parties.”

RECITALS

A. Vicuron is a biopharmaceutical company that discovers, develops and manufactures medicines for hospital-based infectious diseases. On September 14, 2005, Pfizer Inc. acquired Vicuron (formerly known as Versicor Inc.), the successor to Biosearch Italia (“Biosearch”), an Italian pharmaceutical company. Biosearch discovered and partly developed a proprietary compound named Ramoplanin. Vicuron is now a wholly-owned subsidiary of Pfizer.

B . Oscient is a biopharmaceutical company committed to the clinical development and commercialization of novel therapeutics to address unmet medical needs and is interested in completing the development of Ramoplanin and commercializing Ramoplanin.

C. On October 8, 2001 Biosearch entered into a License and Supply Agreement with Oscient to permit the latter to develop and commercialize in the United States and Canada (including the territories and possessions of each such country) Ramoplanin for the treatment or prevention of any human disease (together with Amendment No. 1 dated as of August 8, 2002 and the letter agreement dated as of October 22, 2002, the “License and Supply Agreement”).

D. Oscient and Vicuron (who has assumed the rights and obligations of Biosearch under the License and Supply Agreement by virtue of the merger of Versicor and Biosearch) wish to terminate the License and Supply Agreement and simultaneously enter into a new agreement by which, among other actions, Vicuron will assign to Oscient certain property related to Ramoplanin on the terms and conditions set forth in this Agreement.

ARTICLE 1

DEFINITIONS

The following terms shall have the following meanings as used in this Agreement:

1.1 “Affiliate” means an entity that, directly or indirectly, through one or more intermediaries, controls, is controlled by or is under common control with Vicuron or Oscient, as the case may be.

1.2 “Assigned Property” shall have the meaning set forth in Section 3.1.

1.3 “Bulk Compound” means the bulk form of the Compound meeting the Specifications and used to manufacture Product.

1.4 “Commercialization” shall mean all activities undertaken by Oscient or its designees relating to the manufacture and sale of Product in the Territory, including advertising, education, marketing, distribution and post-approval product support clinical studies conducted after Regulatory Approval of a Product for a particular indication.

1.5 “Compound” means the compound known as Ramoplanin, as described in *****.

1.6 “Control” means possession of the ability to grant rights as provided for herein without violating the terms of any agreement or other arrangement with any Third Party.

1.7 “Derivative Patents” shall mean the patents and patent applications listed on Schedule 1.7 and all related patent applications, including divisions, reissues, continuations, continuations-in-part, re-examination applications and extensions thereof and all foreign counterpart patents and patent applications.

1.8 “Development” means all activities relating to obtaining Regulatory Approval of a Product, Product delivery systems and new indications thereof and all activities relating to developing the ability to manufacture the same.

1.9 “Excluded Trademarks” means those trademarks listed on Schedule 1.9 .

1.10 “FDA” means the United States Food and Drug Administration or any successor agency thereto.

1.11 “Former Partner” shall mean that certain company with which Biosearch entered into a License and Supply Agreement dated May 8, 1998 and an amendment thereto effective as of June 1, 2001.

1.12 “Global Trademarks” means all trademarks except for Excluded Trademarks, including without limitation any registrations and common law rights associated therewith, and any goodwill associated with any of the foregoing, used for or in connection with Products, Bulk Compound, and Compound.

1.13 “Global Tradenames” means all tradenames, including without limitation any registrations and common law rights associated therewith, and any goodwill associated with any of the foregoing, used for or in connection with Products, Bulk Compound, and Compound.

1.14 “IND” (or “Investigational New Drug Application”) means an application as defined in the United States Food, Drug and Cosmetic Act and applicable regulations promulgated thereunder to the FDA or the equivalent application to the equivalent agency in jurisdictions outside the United States, the filing of which is necessary to commence clinical testing of Products in humans.

1.15 “Information” means any and all techniques and data, inventions, discoveries, practices, processes, methods, knowledge, results, trade secrets or other know-how, skill, experience, test data including pharmacological, toxicological, non-clinical and clinical data, medical literature compilations, and analytical and quality control data or descriptions.

1.16 “Joint Patent” means any inventions made jointly by personnel of Vicuron (or its Affiliates) and Oscient under the License and Supply Agreement.

* Confidential information has been omitted and filed separately with the Securities and Exchange Commission pursuant to a confidential treatment request.

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1.17 “Materials” means any and all (i) compounds, compositions of matter, strains, cell lines and banks, assays and biological materials, including *****, and other related proprietary strains, and (ii) all other documents, files, diagrams, specifications, designs, schematics, reports, records, laboratory notebooks, manufacturing and other materials, packaging, commercial and market information, prototypes, test devices, models or simulations, or other written, graphic, biologic or other tangible material in any medium.

1.18 “NDA” means an application as defined in the United States Food, Drug and Cosmetic Act and applicable regulations promulgated thereunder to the FDA, or the equivalent application to the equivalent agency in jurisdictions outside the United States, the filing of which is necessary to commence the commercial sale of Products.

1.19 “Net Sales” means the gross sales with respect to a Product in final dosage form by Oscient, its Affiliates or its licensees to a Third Party end user, based upon the approval received from the FDA or RHA, less (i) discounts, including cash discounts, and/or rebates (including government-mandated rebates), retroactive price reductions or allowances actually allowed or granted from the billed amount, (ii) credits or allowances actually granted upon claims, rejections or returns of such Products, including recalls, (iii) freight, postage, shipping and insurance charges paid for delivery of Product, to the extent both billed and Oscient bears the cost of freight and insurance for a Product, and (iv) taxes (except income taxes), duties or other governmental charges levied on or measured by the billing amount when included in billing, as adjusted for rebates and refunds. Net Sales shall be determined from books and records maintained in accordance with generally acceptable accounting principles in the United States, consistently applied.

In the event Vicuron is receiving royalties under this Agreement from any Product sold in the form of a combination product containing one or more active ingredients in addition to the Compound, Net Sales for such combination product will be calculated by multiplying actual Net Sales by the fraction A/(A+B) where A is the fair market value of the portion of the combination product that contains the Compound and B is the fair market value of the other active ingredients included in such combination product, as determined by market prices of such portions if separately priced and sold. If, on a country-by-country basis, the other active ingredient or ingredients in the combination are not sold separately in that country, Net Sales shall be calculated by multiplying actual Net Sales of such combination product by the fraction A/C where A is the fair market value of the Product if sold separately, and C is the fair market value of the combination product. If, on a country by country basis, neither the Product nor the other active component or components of the combination product is sold separately in said country, Net Sales shall be determined by mutual agreement of both the parties acting in good faith. As used herein, the term “active ingredient” does not include ingredients the primary effect of which is the enhancement of drug delivery, even if such ingredients have pharmacological activity.

1.20 “New Territory” means all countries and territories worldwide other than those included in the Original Territory.

1.21 “Original Territory” means the United States and Canada and the territories and possessions of each of the foregoing countries.

1.22 “Patent” means (i) valid and enforceable patents, re-examinations, reissues, renewals, extensions, term restorations and foreign counterparts thereof, and (ii) pending (at any time during the term of this Agreement) patent applications and foreign counterparts thereof.

1.23 “Patent Rights” means any and all (a) U.S. or foreign patents, (b) U.S. or foreign patent applications, including, without limitation, all provisional applications, substitutions, continuations, continuations-in-part, divisions, renewals, and all patents granted thereon, (c) all patents-of-addition, reissues, reexaminations and extensions or restorations by existing or future extension or restoration mechanisms, including, without limitation, supplementary protection certificates or the equivalent of any of the foregoing, (d) any other form of government-issued right substantially equivalent to any of the foregoing, and (e) any and all foreign counterparts of the foregoing.

* Confidential information has been omitted and filed separately with the Securities and Exchange Commission pursuant to a confidential treatment request.

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1.24 “ Product” means any product including or incorporating any formulation of the Compound.

1.25 “Regulatory Approval” means any and all approvals (including pricing and reimbursement approvals, if appropriate), product and/or establishment licenses, registrations, authorizations, or designations of any federal, state or local regulatory agency, department, bureau or other governmental entity, necessary or used for the Development, manufacture, use, or storage of Products in a regulatory jurisdiction, including, without limitation, INDs, NDAs, any fast track or orphan drug designation or other similar designations, and data or market exclusivity .

1.26 “Regulatory Filing” means any and all filings, submissions or communications with or to the FDA or RHA which relate to the Product or Regulatory Approvals, whether or not obtained, and any other documents related thereto, including without limitation any filings, submissions, communications or documents associated with an IND, NDA or fast track or orphan drug designation.

1.27 “ RHA ” means any relevant government health authority (or successor agency thereto) in any country, other than the FDA, whose Regulatory Approval is necessary to market and sell the Product in the relevant country of the Territory.

1.28 “ Royalty ” shall have the meaning set forth in Section 7.1.

1.29 “ Specifications ” means the current specifications for Bulk Compound as attached to this Agreement as Exhibit I.

1.30 “ Territory ” means all countries and territories worldwide.

1.31 “Third Party ” means any entity other than Vicuron or Oscient or their Affiliates.

1.32 “Vicuron Know-how and Materials” means any and all Information and Materials owned or Controlled by Vicuron that is directly related to or is used solely in connection with the Bulk Compound, Compound, or Products, or the manufacturing, Development or Commercialization thereof. Without limiting the foregoing, Vicuron Know-how and Materials does not include Information and Materials that is developed or acquired by Vicuron or its Affiliates if such Information and Materials have only an incidental, and not direct, relationship to any Bulk Compound, Compound or Products.

1.33 “ Vicuron Licensed Know-how and Materials” means any and all Information and Materials owned or Controlled by Vicuron that is not Vicuron Know-how and Materials and that is necessary, required, or used in connection with the manufacturing, Development and Commercialization of Bulk Compound, Compound, and Products.

1.34 “Vicuron Patents” means the patents listed on Schedule 3.1(a) hereto.

1.35 “Vicuron Regulatory Approvals” means those Regulatory Approvals owned or Controlled by Vicuron.

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ARTICLE 2

TERMINATION

2.1 Termination of the License and Supply Agreement; New Agreement. The Parties agree that this Agreement shall supercede the License and Supply Agreement, which shall be and hereby is terminated as of the Effective Date, and, notwithstanding any provisions of the License and Supply Agreement to the contrary, no rights, obligations or liabilities of the Parties under the License and Supply Agreement shall survive this termination except for the rights, obligations and liabilities of both Parties under Sections 12.2 (Representations), 13 (“Indemnification”) and 14 (“Miscellaneous”) and Vicuron’s obligations or liabilities under Section 9 (“Confidentiality”) thereof.

ARTICLE 3

ASSIGNMENT AND LICENSE

3.1 Assignment of Property. Vicuron hereby sells, transfers, and assigns to Oscient the following rights, free and clear of any liens, charges, claims, encumbrances or restrictions whatsoever (“Assigned Property”):

(a) all of Vicuron’s rights, title, and interests in and to the Vicuron Patents listed on Schedule 3.1(a) to this Agreement, and all Patent Rights issuing or arising therefrom, to the full end of their terms (“Assigned Patents”);

(b) all of Vicuron’s rights, title and interests in and to the Vicuron Know-how and Materials (“Assigned Know-how”);

(c) all of Vicuron’s rights, title and interests in and to the Global Trademarks and Global Tradenames, including those listed on Schedule 3.1(c) to this Agreement;

(d) all of Vicuron’s rights, title and interests in and to Regulatory Filings and Vicuron Regulatory Approvals;

(e) any other rights, title and interests of Vicuron that are necessary or used in the Development, Commercialization, and manufacture of the Bulk Compound, Compound, and Products; and

(f) any and all causes of action, claims, demands or other rights, occasioned from or because of any and all past and future infringement, misappropriation, dilution or any other violation of rights of any of the Assigned Property, including all rights to recover damages, profits and injunctive relief for infringement of any of the Assigned Property.

3.2 Further Assurances. Vicuron shall execute and sign such further assignments, including the patent and trademark assignment forms provided in Exhibits II and III, respectively, instruments, applications and documents, and do or cause to be done such other acts and things, as may reasonably be required by Oscient to effectively vest in Oscient all of the Assigned Property, except that Vicuron shall not be required to file any patent or trademark assignments with any governmental authorities or agencies anywhere in the Territory.

3.3 No Assumption of Liabilities or Obligations.

(a) Except as expressly set forth in this Agreement, Oscient is not assuming and shall not be liable for any contractual obligations of Vicuron or its Affiliates or any other liabilities or obligations of Vicuron or its Affiliates of any nature, fixed or contingent, disclosed or undisclosed, to the extent that such liabilities or obligations arose, or related to an act, omission or breach occurring, prior to the Effective Date, which such liabilities or obligations pertain to the Assigned Property or arise from the consummation of the transactions contemplated hereunder, all of which liabilities and obligations shall remain the sole responsibility of Vicuron.

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(b) Except as expressly set forth in this Agreement, Vicuron is not assuming and shall not be liable for any contractual obligations of Oscient or its Affiliates or any other liabilities or obligations of Oscient or its Affiliates of any nature, fixed or contingent, disclosed or undisclosed, to the extent that such liabilities or obligations arose, or related to an act, omission or breach occurring, on or following the Effective Date, which such liabilities or obligations pertain to the Assigned Property or arise from the consummation of the transactions contemplated hereunder, all of which liabilities and obligations shall be sole responsibility of Oscient.

3.4 License . Vicuron hereby grants to Oscient a worldwide, irrevocable, royalty-free, non-exclusive license, with the right to sublicense under the Vicuron Licensed Know-how and Materials, to manufacture, Develop and Commercialize Bulk Compound, Compound, and Products; provided , however , that in the event that Vicuron is required to pay any fees associated with Oscient’s use of any Vicuron Licensed Know-how and Materials on or following the Effective Date, Vicuron will notify Oscient of such fees and if Oscient agrees in writing to obtain such license, Vicuron and Oscient will negotiate in good faith to determine the amount of royalty or other payment due to Vicuron in consideration for the license granted pursuant to this Section 3.4.

3.5 Right of Negotiation for Derivative Patents. The Parties further agree that, if Vicuron has not licensed all or a portion of its rights under a Derivative Patent to a Third Party, or assigned or otherwise transferred a Derivative Patent to a Third Party on or before the ***** of the Effective Date (“Option Date”), Oscient may request within a ***** day period following the Option Date to discuss with Vicuron the terms upon which Oscient will accept the assignment of such Derivative Patent. The Parties shall meet after such request and negotiate in good faith the potential terms of an agreement on such terms. If the Parties do not enter into such an agreement within ***** days after Oscient so requests to negotiate such opportunity with Vicuron (“Negotiation Period”), then Vicuron shall thereafter be free to offer such opportunity to a Third Party with respect to such Derivative Patent; provided, however, that Vicuron shall not enter into any agreement with any Third Party with respect to such Derivative Patent on terms that are more favorable to such Third Party than those last offered by Vicuron to Oscient during the Negotiation Period. In the event that Vicuron does not enter into any agreement with any Third Party with respect to such Derivative Patent within ***** days after the Negotiation Period, Vicuron and Oscient shall enter into an agreement on terms last offered by Oscient during the Negotiation Period. Vicuron agrees to give Oscient prompt notice in writing if Vicuron licenses or assigns all or a portion of its rights under any Derivative Patent to a Third Party.

ARTICLE 4

EXECUTION FEE; MILESTONE PAYMENTS

4.1 Execution Fee. As partial payment for the Assigned Property granted by Vicuron pursuant to Article 3 of this Agreement, Oscient shall pay to Vicuron, within two (2) business days after the Effective Date, ***** Dollars (U.S.$ *****), cash by wire transfer (same value date).

4.2 Milestone Payments for Original Territory. Oscient or its licensee shall make the following milestone payments to Vicuron within ten (10) business days after the first achievement of each of the following milestones with respect to the Product in the Original Territory:

* Confidential information has been omitted and filed separately with the Securities and Exchange Commission pursuant to a confidential treatment request.

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4.3 Milestone Payments for New Territory. Oscient or its licensee shall make the following milestone payments to Vicuron within ten (10) business days after the first achievement of each of the following milestones with respect to the Product in the New Territory:

Any grant by Oscient of a license to a Third Party shall not affect Vicuron’s right to receive milestone payments as provided in Sections 4.2 and 4.3. Oscient shall remain responsible for the payments due to Vicuron pursuant to Sections 4.2 and 4.3 in the event it grants any such license. The payment amounts are nonrefundable and noncreditable.

ARTICLE 5

TECHNOLOGY TRANSFER

5.1 Transfer of Vicuron Know-how and Materials.

(a) Within thirty (30) days of the Effective Date, Vicuron shall deliver and transfer to Oscient, or Oscient’s designee, all Vicuron Know-how and Materials, Vicuron Licensed Know-how and Materials, and Regulatory Filings to a location designated by Oscient and in accordance with commercially reasonable procedures for a transfer of this type. Vicuron will provide Oscient with all reasonable assistance required to transfer the Vicuron Know-how and Materials, Vicuron Licensed Know-how and Materials, Regulatory Filings and Vicuron Regulatory Approvals, and the benefit thereof, to Oscient or Oscient’s designee. Without limiting the generality of the foregoing, (a) Vicuron shall provide Oscient or its designee with all Information and Materials in its possession necessary to enable it to manufacture the Bulk Compound and Product, and (b) if visits with personnel of Vicuron and its Affiliates are reasonably requested by Oscient for purposes of transferring the Vicuron Know-how and Materials, Vicuron Licensed Know-how and Materials, Regulatory Filings and Vicuron Regulatory Approvals to Oscient or its designee, or for purposes of Oscient’s acquiring expertise on the practical application and use of the Vicuron Know-how and Materials, Vicuron Licensed Know-how and Materials, Regulatory Filings or Vicuron Regulatory Approvals or of assisting Oscient or its designee on issues arising during such transfer and transition, then, on a reasonable schedule to be agreed upon by the Parties, qualified personnel from each Party with appropriate technical or regulatory expertise who are familiar with all aspects of the Vicuron Know-how and Materials, Vicuron Licensed Know-how and Materials, Regulatory Filings and Vicuron Regulatory Approvals shall meet at such facilities or locations as may be mutually agreed upon, and shall participate in telephone conference calls so that the personnel from Vicuron can transfer knowledge to Oscient personnel about manufacture of the Products. The Parties now anticipate that these in-person meetings shall occur at mutually agreed locations and that telephone conference calls shall occur regularly for a period of at least ***** months from the Effective Date, it being agreed that there shall be no more than ***** days of in-person meetings during such *****-month period unless the Parties agree to additional meetings. Notwithstanding the foregoing, until Oscient or its designee *****, Vicuron shall make available to Oscient Vicuron’s then-current employees or then-current consultants who have expertise or knowledge relevant to the manufacture of Bulk Compound on a reasonable schedule to be agreed upon by the Parties. The transfer of Vicuron Know-how and Materials and Vicuron Licensed Know-how and Materials to Oscient shall be complete only upon Vicuron’s

* Confidential information has been omitted and filed separately with the Securities and Exchange Commission pursuant to a confidential treatment request.

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satisfaction of the foregoing requirements. Vicuron and its Affiliates agree to cooperate with Oscient and applicable regulatory authorities to the extent reasonably necessary to effect the successful transfer of Regulatory Filings and Vicuron Regulatory Approvals.

(b) As of the Effective Date, Vicuron has designated Jeffrey Meckler as its primary contact person and Oscient has designated Diane McGuire as its primary contact person. The primary contact persons shall be responsible for oversight of the interactions and activities described in Section 5.1(a) and shall attempt to resolve any questions that arise during the course of such transfer.

ARTICLE 6

BULK COMPOUND

6.1 Transfer of Bulk Compound. Vicuron agrees to provide Oscient with any or all of the Bulk Compound for no additional consideration. Vicuron estimates there is approximately ***** kg of Bulk Compound.

ARTICLE 7

ROYALTIES; PAYMENT PROCEDURES AND RECORDS

7.1 Royalties. Oscient shall pay to Vicuron a royalty equal to (a) ***** percent (*****%) of Net Sales in the Original Territory and (b) ***** percent (*****%) of Net Sales in the New Territory (collectively “Royalty”).

7.2 Sales by Licensees. If Oscient grants a license under the rights granted to it pursuant to Article 3, then such license shall include an obligation for the licensee to account for and report to Oscient its Net Sales of such Products on the same basis as if such sales were Net Sales by Oscient, and Oscient shall pay Royalties to Vicuron on such sales as if the Net Sales of the licensee were Net Sales of Oscient.

7.3 Royalty Reports.

(a) Oscient will deliver to Vicuron a report showing in detail its calculation of the Net Sales and quantities of any Products sold by Oscient during a given calendar quarter within ***** days following the end of such quarter for which Royalty payments are due from Oscient. Oscient shall pay the Royalty due on Net Sales during the calendar quarter covered by a given report under this Section 7.3 simultaneously with the delivery of such report to Vicuron.

(b) Oscient will deliver to Vicuron a report showing in detail its calculation of the Net Sales and quantities of any Products sold by Oscient’s licensees during a given calendar quarter to Vicuron within ***** business days following Oscient’s receipt of such report by its licensees. Oscient shall pay the amounts due to Vicuron on Net Sales by Oscient’s licensees pursuant to Section 7.2 simultaneously with the delivery of such report to Vicuron. Oscient shall use reasonable efforts to have licensees provide such report in a timely fashion after the end of each calendar quarter and each calendar year.

7.4 Exchange Rate; Manner and Place of Payment. All amounts paid to Vicuron hereunder shall be paid in United States currency. Net Sales shall be accounted for on a monthly basis in U.S. Dollars at the spot rate of exchange published by the Board of Governors of the Federal Reserve System in Statistical Release H.10 (http://www.federalreserve.gov/releases/H10) for each month on the last banking day of such month. All payments due to Vicuron under this