GTC Biotherapeutics Enters Agreements with LFB for Funding of $12.3 Million with an Option for LFB to Fund an Additional $6.4 Million

Business Wire, June 18, 2009

About LFB

LFB is a biopharmaceutical group that develops, manufactures and markets medicinal products for the treatment of serious and often rare diseases in several major therapeutic fields, namely Hemostasis, Immunology and Intensive Care. LFB Group is the leading manufacturer of plasma-derived medicinal products in France and 6th worldwide and is also among the leading European companies for the development of monoclonal antibodies and new-generation proteins based on biotechnologies. With its strong focus on research, the LFB Group is pursuing a growth strategy that seeks to extend its activities at international level and develop innovative therapies. In 2008, LFB reported total turnover of 352,4 million euros, an increase of 9% and invested 66,6 millions euros in product development. LFB markets its products in 20 countries round the world.

IMPORTANT INFORMATION

GTC intends to file a proxy statement and other relevant documents with the Securities and Exchange Commission (the "SEC") in connection with seeking the necessary shareholder approvals to complete the financing discussed above. GTC shareholders should read the proxy statement and other relevant documents when they become available because they will contain important information about the financing and the related proposals. The proxy statement, any amendments or supplements to the proxy statement, and other relevant documents filed by GTC with the SEC will be available free of charge at the SEC’s website, www.sec.gov, and at the GTC’s website, www.gtc-bio.com. Copies of these documents will also be available free of charge by submitting a written request to GTC Biotherapeutics, Inc., 175 Crossing Boulevard, Framingham, MA 01702, ATTN: Investor Relations. GTC, its directors and certain of its executive officers may be deemed participants in the solicitation of proxies from GTC’s shareholders with respect to the proposals related to the financing. Information about GTC’s directors and executive officers and their respective interests in the financing will be set forth in the proxy statement that GTC will file with the SEC in connection with seeking the necessary shareholder approvals to complete the financing. Additional information regarding GTC’s directors and executive officers is also included in GTC’s definitive proxy statement for its 2009 annual meeting, which was filed with the SEC on April 23, 2009, and is available by the means described above.

Forward-Looking Statement

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, including without limitation the prospects for shareholder approval, conversion of the preferred stock, and the potential for additional convertible preferred stock investment by LFB through exercise of the option it will obtain upon shareholder approval and closing of the first issuance of convertible preferred stock. 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 risks and uncertainties associated with dependence upon approval of the transactions by shareholders and the actions regulatory agencies. 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.