FRAMINGHAM, MA – December 10, 2008 – Shareholders of GTC Biotherapeutics, Inc. ("GTC", Nasdaq: GTCB) have approved three proposals required to complete an agreement with LFB Biotechnologies for a $15 million financing in which GTC will issue convertible debt and warrants to purchase shares of GTCB common stock. The financing, which will be for GTC’s corporate purposes across all programs, is scheduled to close upon completion of an intercreditor agreement between LFB and GE Capital and satisfaction of other customary closing conditions. GTC expects net proceeds at closing, after transaction costs and establishment of a restricted cash account, to be approximately $10 million.

• The issuance to LFB of a $15 million secured convertible note and a warrant to purchase shares of common stock.
• An increase of 2,000,000 in the number of shares of common stock reserved under GTC’s 2002 Equity Incentive Plan.
• An increase of 10,000,000 in the number of GTC’s authorized shares of common stock.

Under the agreement with LFB, the convertible debt will mature on June 30, 2012, and will bear interest at an annual rate of 8%. The debt may be converted into GTC common stock at $0.31 per share at LFB’s discretion at any time after June 1, 2009. GTC has the right to redeem the debt on or before June 1, 2009. GTC will also issue to LFB 5-year warrants to purchase approximately 23.2 million shares of GTCB common stock at $0.31 per share. If the debt is repaid in full, LFB will have the right to require GTC to redeem the warrants for an aggregate price of $1.5 million. As a condition of the financing, $4 million of the proceeds will be placed in a restricted cash account to secure GTC’s existing debt to GE Capital.

The convertible debt will be secured by a first lien on GTC’s intellectual property and a second lien on all of GTC’s other assets except for the restricted cash account for GE Capital. In addition, the debt will be secured by a grant of rights and licenses with respect to certain products, including GTC’s co-exclusive rights under its collaboration agreement with LFB. The convertible debt will be subordinated to the current term debt with GE Capital.

GTC Biotherapeutics develops, supplies, and commercializes therapeutic proteins produced through transgenic animal technology. ATryn®, GTC’s recombinant human antithrombin, has been approved for use in Europe and has begun the review process in the United States under a Biologics License Application. In addition to ATryn®, GTC is developing a portfolio of recombinant human plasma proteins with known therapeutic properties. These proteins include recombinant forms of human coagulation factors VIIa and IX, which are used for the treatment of hemophilia, and alpha-1 antitrypsin. GTC also has a monoclonal antibody portfolio that includes a monoclonal antibody to CD20 and a monoclonal antibody to CD137. GTC is collaborating with LFB on the factor VIIa, factor IX, alpha-1 antitrypsin, and CD20 monoclonal antibody programs. GTC’s intellectual property includes a patent in the United States through 2021 for the production of any therapeutic protein in the milk of any transgenic mammal. GTC’s transgenic production platform is particularly well suited to enabling cost effective development of proteins that are difficult to express in traditional recombinant production systems as well as proteins that are required in large volumes. Additional information is available on the GTC web site, http://www.gtc-bio.com.

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, including without limitation statements regarding GTC’s ability to satisfy any of the other conditions to completing the LFB financing, the timing of the financing, and the potential for further success in GTC’s continuing partnering strategy. Such forward-looking statements are subject to a number of risks, uncertainties and other factors that could cause actual results to differ materially from future results expressed or implied by such statements. Factors that may cause such differences include, but are not limited to, the risks and uncertainties discussed in GTC's most recent Annual Report on Form 10-K and its other periodic reports filed with the Securities and Exchange Commission, including the uncertainties associated with dependence upon the actions of partners. GTC cautions investors not to place undue reliance on the forward-looking statements contained in this release. These statements speak only as of the date of this document, and GTC undertakes no obligation to update or revise the statements, except as may be required by law.