AMENDED AND RESTATED SECURITY AGREEMENT

Exhibit 10.2

AMENDED AND RESTATED SECURITY AGREEMENT

THIS AMENDED AND RESTATED SECURITY AGREEMENT (this “ Agreemen t”) dated as of the 18th day of June, 2009 and effective as of December 22, 2008 with respect to the below-defined 2008 Convertible Note, the below-defined 2008 Purchase Agreement and all obligations related thereto, from GTC BIOTHERAPEUTICS, INC. (“ Debtor ”) in favor of LFB BIOTECHNOLOGIES S.A.S. (together with its successors and assigns, if any, “ Secured Party ”). Secured Party has an office at 3, avenue des Tropiques, Les Ulis, Courtaboeuf, France. Debtor is a corporation organized and existing under the laws of the Commonwealth of Massachusetts (the “ State ”). Debtor’s mailing address and chief place of business is 175 Crossing Blvd., Framingham, MA 01702.

RECITALS:

WHEREAS , the Debtor issued and sold to the Secured Party a subordinated convertible note dated as of December 14, 2006 in the original principal amount of $2,558,650 (the “ 2006 Convertible Note ”).

WHEREAS , pursuant to that certain Note and Warrant Purchase Agreement by and between the Debtor and the Secured Party dated as of October 31, 2008 (the “ 2008 Purchase Agreement ”), the Debtor issued and sold to the Secured Party a secured convertible note dated as of December 22, 2008 in the original principal amount of $15,000,000 (the “ 2008 Convertible Note ”) and that certain Warrant dated as of December 22, 2008 (the “ Warrant ”) to purchase up to 23,193,548 shares of common stock of the Debtor.

WHEREAS , it was a condition to the 2008 Purchase Agreement that the Debtor execute and deliver the Security Agreement dated as of December 22, 2008 from Debtor in favor of Secured Party (the “ Original Security Agreement ”), pursuant to which the obligations of the Debtor to the Secured Party under the 2008 Purchase Agreement and the 2008 Convertible Note were secured.

WHEREAS , subject to the terms and conditions of that certain Securities Purchase Agreement dated as of the date hereof by and between the Debtor and the Secured Party (the “ 2009 Purchase Agreement ”), the Debtor intends to issue and sell to the Secured Party a secured convertible note dated as of the date hereof in the original principal amount of $4,512,268 (the “ 2009 Convertible Note ”).

WHEREAS, pursuant to that certain Loan Agreement dated as of the date hereof between the Debtor and Secured Party and subject to the satisfaction of the conditions contained therein, the Secured Party has committed to make a term loan to the Debtor in the aggregate principal amount of $3,500,000 and in connection therewith the Debtor is issuing to the Secured Party a promissory note dated as of the date hereof in the original principal amount of $3,500,000 (the “ Secured Note ”, and together with the 2006

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Convertible Note, the 2008 Convertible Note and the 2009 Convertible Note, collectively, the “ Notes ”).

WHEREAS , in connection with the issuance of the Secured Note and the 2009 Convertible Note, the Debtor is amending and restating the Original Security Agreement in its entirety and delivering this Agreement in favor of Secured Party, pursuant to which all debts, obligations and liabilities of the Debtor to the Secured Party are secured, including without limitation, the obligations under the 2008 Purchase Agreement, the 2009 Purchase Agreement, the Loan Agreement, the 2006 Convertible Note, the 2008 Convertible Note, the 2009 Convertible Note and the Secured Note.

NOW, THEREFORE , in consideration of the mutual covenants and undertakings herein contained, Debtor and Secured Party agree as follows:

Debtor grants to Secured Party, its successors and assigns, a continuing security interest in, to and against all property listed on any collateral schedule now or in the future annexed to or made a part of this Agreement (“ Collateral Schedule ”), including without limitation the property listed on Collateral Schedule No. 1, whether now owned or existing or hereafter acquired or arising and wheresoever located, and in and against all additions, attachments, accessories and accessions to such property, all substitutions, replacements or exchanges therefor, and all proceeds or products thereof, in whatever form, including without limitation cash, deposit accounts (whether or not comprised solely of proceeds), certificates of deposit, insurance proceeds (including hazard, flood and credit insurance), negotiable instruments for the payment of money, chattel paper, security agreements, documents, eminent domain proceeds, condemnation proceeds and/or tort claim proceeds (all such property is individually and collectively called the “ Collateral ”). This security interest is given to secure the payment and performance of all debts, obligations and liabilities of any kind whatsoever (including all interest (whether or not allowed or disallowed), charges, expenses, fees and other sums accruing after commencement of any case, proceeding or other action relating to the bankruptcy, insolvency or reorganization of Debtor) of Debtor to Secured Party, now existing or arising in the future, including without limitation, the debts, obligations and liabilities of Debtor to Secured Party in connection with the payment and performance of the 2006 Convertible Note, the 2008 Convertible Note, the 2009 Convertible Note, the Secured Note, the 2008 Purchase Agreement (excluding the Warrant), the 2009 Purchase Agreement, the Loan Agreement, that certain Trademark and License Security Agreement by and between the Debtor and the Secured Party dated as of December 22, 2008 (the “ Trademark Security Agreement ”), that certain Patent and License Security Agreement by and between the Debtor and the Secured Party dated as of December 22, 2008 (the “ Patent Security Agreement ”), and that certain Second Mortgage, Security Agreement and Fixture Filing dated December 22, 2008 granted by Debtor to Secured Party, as amended by that certain Amendment to Mortgage, Security Agreement and Fixture Filing dated as of the date hereof (as so amended, the “ Mortgage ”), together with all Schedules and attachments thereto and any renewals, extensions, modifications, amendments and/or restatements of any such debts, obligations and liabilities (such

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Notes, the 2008 Purchase Agreement, the 2009 Purchase Agreement, Loan Agreement, Trademark Security Agreement, Patent Security Agreement, Mortgage, Schedules, debts, obligations and liabilities are called the “ Indebtedness ”).

Debtor represents, warrants and covenants as of the date of this Agreement and as of the date of each Collateral Schedule that:

(a) Debtor’s exact legal name is as set forth in the preamble of this Agreement and Debtor is, and will remain, duly organized, existing and in good standing under the laws of the State set forth in the preamble of this Agreement, has its chief executive offices at the location specified in the preamble, and is, and will remain, duly qualified and licensed in every jurisdiction wherever necessary to carry on its business and operations. As of the date hereof, GTC Holding Ltd., an exempted company incorporated with limited liability under the laws of the Cayman Islands, is the only Subsidiary of the Debtor that is a “significant subsidiary” as determined in accordance with Regulation S-X;

(b) Debtor has adequate power and capacity to enter into, and to perform its obligations under this Agreement, each Note, the Patent Security Agreement, the Trademark Security Agreement, the Mortgage, the Warrant, the Loan Agreement, and any other documents evidencing, or given in connection with, any of the Indebtedness (all of the foregoing are called the “ Debt Documents ”);

(c) This Agreement and the other Debt Documents have been duly authorized, executed and delivered by Debtor and constitute legal, valid and binding agreements enforceable in accordance with their terms, except to the extent that the enforcement of remedies may be limited under applicable bankruptcy and insolvency laws and general principles of equity;

(d) No approval, consent or withholding of objections is required from any governmental authority or instrumentality with respect to the entry into, or performance by Debtor of any of the Debt Documents, except any already obtained;

(e) The entry into, and performance by, Debtor of the Debt Documents will not (i) violate any of the organizational documents of Debtor or any judgment, order, law or regulation applicable to Debtor or (ii) result in any breach of or constitute a default under any contract or agreement to which Debtor is a party, or result in the creation any lien, claim or encumbrance on any of Debtor’s property (except for liens in favor of Secured Party) pursuant to any indenture, mortgage, deed of trust, bank loan, credit agreement or other agreement or instrument to which Debtor is a party;

(f) Except as set forth on Schedule 2(f) attached hereto, there are no suits or proceedings pending in court or before any commission, board or other administrative agency against or affecting Debtor which could, in the aggregate, have a material adverse effect on Debtor, its business or operations, or its ability to perform its obligations under

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the Debt Documents, nor does Debtor have reason to believe that any such suits or proceedings are threatened;

(g) All financial statements delivered to Secured Party in connection with the Indebtedness have been prepared in accordance with generally accepted accounting principles, except that quarterly financial statements will not provide footnotes and will be subject to normal year-end adjustments, and since the date of the most recent financial statement, except as disclosed in the Debtor’s most recently filed periodic report with the Securities and Exchange Commission (“ SEC ”), there has been no material adverse change in Debtor’s financial condition;

(h) The Collateral is not, and will not be, used by Debtor for personal, family or household purposes;

(i) The Collateral is, and will remain, in good condition and repair (ordinary wear and tear excepted), and Debtor will not be negligent in its care and use;

(j) Debtor is, and will remain, the sole and lawful owner, and in possession of (other than the Offsite Collateral (defined below) (solely with respect to possession)), the Collateral, and has the sole right and lawful authority to grant the security interest described in this Agreement;

(k) The Collateral is, and will remain, free and clear of all liens, claims and encumbrances of any kind whatsoever, except for (i) liens in favor of Secured Party, (ii) liens existing as of the date of this Agreement and set forth on Schedule 2(k) attached hereto, (iii) liens for taxes not yet due or for taxes being contested in good faith and which do not involve, in the judgment of Secured Party, any risk of the sale, forfeiture or loss of any of the Collateral and with respect to which adequate reserves have been set aside for the payment thereof in accordance with GAAP, (iv) liens relating to purchase money financings that have been entered into in the ordinary course of business, and (v) inchoate materialmen’s, mechanic’s, repairmen’s and similar liens arising by operation of law in the normal course of business for amounts which are not delinquent (all of such liens are called “ Permitted Liens ”);

(l) Debtor is and will remain in full compliance with all laws and regulations applicable to it including without limitation (i) ensuring that no person who owns a controlling interest in or otherwise controls Debtor is or shall be (A) listed on the Specially Designated Nationals and Blocked Person List maintained by the Office of Foreign Assets Control (“ OFAC ”), Department of the Treasury, and/or any other similar lists maintained by OFAC pursuant to any authorizing statute, Executive Order or regulation or (B) a person designated under Section 1(b), (c) or (d) of Executive Order No. 13224 (September 23, 2001), any related enabling legislation or any other similar Executive Orders, and (ii) compliance with all applicable Bank Secrecy Act (“ BSA ”) laws, regulations and government guidance on BSA compliance and on the prevention and detection of money laundering violations;

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(m) Debtor’s and each Subsidiary’s (defined below) Intellectual Property (as defined in Section 7 below) is and will remain free and clear of all liens, claims and encumbrances of any kind whatsoever, except for Permitted Liens as defined in subsection (k) of this Section, the granting of licenses of Debtor’s Intellectual Property in the ordinary course of business and other licensing, partnership or joint ventures entered into in the ordinary course of Debtor’s business and permitted hereunder. For purposes of this Agreement, the term “ Subsidiary ” shall mean a corporation or other entity of which more than 50% of the outstanding stock or other ownership interests having ordinary voting power to elect a majority of the directors (or other persons performing similar functions) of such corporation is owned, directly or indirectly, by Debtor;

(n) Debtor has not and will not, and will not permit any Subsidiary to, enter into any other agreement or financing arrangement in which it grants a negative pledge in Debtor’s or any Subsidiary’s Intellectual Property to any other party;

(o) Debtor agrees that it shall not, and shall not allow any of its Subsidiaries to, directly or indirectly, create, incur, assume, permit to exist, guarantee or otherwise become or remain directly or indirectly liable with respect to, any Debt (as hereinafter defined), except for (i) Debt of Debtor to Secured Party, (ii) Debt existing on the date hereof and set forth on Schedule 2(o) to this Agreement, (iii) Debt (a) secured by a Lien described in Section 2(k)(iv) hereof, (b) related to unsecured letter of credit obligations incurred by Debtor in the ordinary course of its business and (c) unsecured obligations to trade creditors incurred in the ordinary course of business and more than ninety (90) days past due, provided , that the amount of such additional Debt permitted by (a)-(c) shall not exceed $1,500,000 in the aggregate, and (iv) Debt pursuant to which the Debtor, the Secured Party and the holder of such debt have entered into a subordination agreement acceptable to the Secured Party, if any (“ Subordinated Debt ”). The term “ Debt ” shall mean, with respect to any person, at any date, without duplication, (A) all obligations of such person for borrowed money, (B) all obligations of such person evidenced by bonds, debentures, notes or other similar instruments, or upon which interest payments are customarily made, (C) all obligations of such person to pay the deferred purchase price of property or services incurred in the ordinary course of business if the purchase price is due more than six (6) months from the date the obligation is incurred, (D) all capital lease obligations of such person, (E) the principal balance outstanding under any synthetic lease, tax retention operating lease, off-balance sheet loan or similar off-balance sheet financing product, (F) all obligations of such person to purchase securities (or other property) which arise out of or in connection with the issuance or sale of the same or substantially similar securities (or property), (G) all contingent or non-contingent obligations of such person to reimburse any bank or other person in respect of amounts paid under a letter of credit or similar instrument, (H) all equity securities of such person subject to repurchase or redemption otherwise than at the sole option of such person, (I) all Indebtedness secured by a lien on any asset of such person, whether or not such Debt is otherwise an obligation of such person, (J) all obligations of such person under any foreign exchange contract, currency swap agreement, interest rate swap, cap or collar agreement or other similar agreement or arrangement designed to alter the risks of that person arising from fluctuations in currency values or interest rates, in each case whether contingent or matured, (K) all obligations or liabilities of others guaranteed by such

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person; and (L) all obligations of such person to trade creditors (other than Genzyme Corporation) incurred in the ordinary course of business and more than ninety (90) days past due;

(p) Debtor agrees that it shall not, and shall not allow any of its Subsidiaries to, (i) make any payment in respect of any Subordinated Debt, except in accordance with any applicable Subordination Agreement or (ii) amend, supplement, modify or waive any of the terms of any document governing any Subordinated Debt. Debtor further agrees to provide Secured Party copies of any notices, reports, financial statements, financial information or other information either delivered or received by Debtor in relation to the Subordinated Debt or pursuant to any subordinated note except to the extent that such information is to be provided to Secured Party under this Agreement or any of the other Debt Documents;

(q) After the Closing Date (as defined in the Loan Agreement), Debtor shall not and shall not allow any of its Subsidiaries to open or maintain any securities, depository or disbursement accounts except upon thirty (30) days’ prior written notice to Secured Party, and Debtor shall not, and shall not allow any Subsidiary to, use any such accounts until such time as the applicable securities intermediary or depository institution, as the case may be, Debtor or such subsidiary of Debtor, as the case may be, and Secured Party have entered into a control agreement satisfactory to Secured Party in its reasonable discretion and in any event sufficient to perfect a first priority lien and security interest in such account in favor of Secured Party. All funds in or transferred into any such account on or after the Closing Date shall be subject to the security interest granted under this Agreement. Each control agreement entered into pursuant to the above shall grant Secured Party control of such securities, depository or disbursement account and provide that the applicable securities intermediary or depository institution, as the case may be, will comply with instructions originated by the Secured Party directing disposition of the funds in such account without further consent by Debtor, provided, that Debtor shall have full access to such accounts and the funds therein until the earlier to occur of (A) an Event of Default or (B) Debtor shall have acted in a fraudulent manner or shall have committed an act of fraud;

(r) Debtor agrees that it shall not, and shall not allow any of its Subsidiaries to, without the prior written consent of Secured Party, which consent shall not be unreasonably withheld, purchase or acquire obligations or stock of, or any other interest in, any corporation or other entity (other than cash equivalents and equity investments in its Subsidiaries existing as of the date hereof), or form any Subsidiary or enter into any partnership, joint venture or similar arrangement; and

(s) Debtor will not, and will not permit any Subsidiary to, directly or indirectly, engage in any transaction with any Affiliate, except where such transactions are (i) on terms that are no less favorable to the Debtor or such Subsidiary than those which might be obtained at the time from unaffiliated third parties and (ii) entered into in the ordinary course of business. As used herein, “ Affiliate ” of any person means (a) any person which, directly or indirectly, is in control of, is controlled by, or is under common control with such person, or (b) any person who is a partner, shareholder, director or

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officer (i) of such person, or (ii) of any person described in clause (a) above, and, for purposes of this definition, control of a person shall mean the power, direct or indirect, (x) to vote 10% or more of the voting equity interests of such person, or (y) to direct or cause the direction of the management and policies of such person whether by contract or otherwise. Notwithstanding the foregoing, Secured Party shall not be considered to be an “Affiliate” of Debtor or any Subsidiary.

(a) Until repossession of Collateral by Secured Party in the exercise of its remedies under Section 7 hereof, Debtor shall remain in possession of the Collateral, other than such portion of the Collateral as shall be located from time to time at the locations in connection with the purification, packaging and storage arrangements more fully described in Schedule 3 attached hereto (the “ Offsite Collateral ”); except that the Secured Party shall have the right to possess (i) any chattel paper or instrument that constitutes a part of the Collateral, and (ii) any other Collateral in which the Secured Party’s security interest may be perfected only by possession. Secured Party may inspect any of the Collateral during normal business hours after giving Debtor reasonable prior notice.

(b) Debtor shall (i) use the Collateral only in its trade or business, (ii) maintain all of the Collateral in good operating order and repair, normal wear and tear excepted, (iii) use and maintain the Collateral only in compliance with manufacturers recommendations and all applicable laws and (iv) keep all of the Collateral free and clear of all liens, claims and encumbrances (except for Permitted Liens).

(c) Secured Party does not authorize and Debtor agrees it shall not, and shall not allow any of its Subsidiaries to, without the prior written consent of Secured Party, which consent shall not be unreasonably withheld:

(i) part with possession of any of its assets (including without limitation in respect of Debtor, the Collateral) (except for (A) the Offsite Collateral, (B) to Secured Party, (C) for maintenance and repair, (D) any sale or disposition of inventory in the ordinary course of business or the sale of equipment or other assets which are determined by the Debtor in good faith to be obsolete or no longer used or useful in Debtor’s business and (E) any non-exclusive licenses of Intellectual Property entered into in the ordinary course of business);

(ii) remove any of the Collateral from the continental United States (except for that portion of the Offsite Collateral which from time to time shall be located in Europe as set forth in Schedule 3 attached hereto or any sale or disposition of inventory in the ordinary course of business); or

(iii) sell, rent, lease, mortgage, license, grant a security interest in or otherwise transfer or encumber (except for Permitted Liens) any of its assets (including, without limitation, in respect of Debtor, the Collateral) (except for (A) any sale or disposition of inventory in the ordinary course of business, (B) the sale of equipment or

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other assets which are determined by the Debtor in good faith to be obsolete or no longer used or useful in Debtor’s business, (C) transfers of Intellectual Property expressly permitted under Section 2(m), and (D) liens on assets financed under capital leases, to the extent such the amount of related capital lease obligations together with other Debt permitted hereunder, do not violate the terms of Section 2(o).

(d) Debtor shall pay promptly when due all taxes, license fees, assessments and public and private charges levied or assessed on any of the Collateral, on its use, or on this Agreement or any of the other Debt Documents. At its option, Secured Party may discharge taxes, liens, security interests or other encumbrances at any time levied or placed on the Collateral and may pay for the maintenance, insurance and preservation of the Collateral and effect compliance with the terms of this Agreement or any of the other Debt Documents. Debtor agrees to reimburse Secured Party, on demand, all reasonable out-of-pocket costs and expenses incurred by Secured Party in connection with such payment or performance and agrees that such reimbursement obligation shall constitute Indebtedness.

(e) Debtor shall, at all times, keep accurate and complete records of the Collateral, and Secured Party shall have the right to inspect and make copies of all of Debtor’s books and records relating to the Collateral during normal business hours, after giving Debtor reasonable prior notice.

(f) Debtor agrees and acknowledges that any third person who may at any time possess all or any portion of the Collateral shall be deemed to hold, and shall hold, the Collateral as the agent of, and as pledge holder for, Secured Party. Secured Party may at any time give notice to any third person described in the preceding sentence that such third person is holding such Collateral as the agent of, and as pledge holder for, the Secured Party.

(g) Upon reasonable notice to Debtor (unless a default or Event of Default has occurred hereunder), Debtor shall permit Secured Party or one or more agents to perform, at Debtor’s expense, appraisals of Collateral, field examinations, collateral analysis, monitoring or other business analysis as reasonable required by Secured Party and sha