Synageva BioPharma Corp ., a privately held biopharmaceutical company developing therapeutic products for rare disorders (“Synageva”), and Trimeris, Inc . (NASDAQ: TRMS) (“Trimeris”) announced today that Trimeris has filed a Form S-4 Registration Statement with the U.S. Securities and Exchange Commission (“SEC”) pertaining to the previously announced merger of Trimeris and Synageva. The Registration Statement has not yet been declared effective, and the information contained therein is subject to change. Once the Registration Statement has been declared effective, Synageva and Trimeris intend to set a date for a special meeting of each of their respective stockholders to approve the merger and deliver the final joint proxy statement/prospectus to their respective stockholders. About Synageva BioPharma Corp. Synageva is a clinical stage biopharmaceutical company focused on the discovery, development, and commercialization of therapeutic products for patients with life-threatening rare diseases and unmet medical need. Its lead program, SBC-102, is a recombinant human lysosomal acid lipase (“LAL”) currently in clinical trials in the U.S. and EU for the treatment of patients with LAL Deficiency, which is a rare and devastating disease that causes significant morbidity and mortality. SBC-102 has been granted orphan designations by the U.S. Food and Drug Administration (“FDA”) and the European Medicines Agency (“EMA”), and fast track designation by the FDA. Synageva has several protein therapeutics in its pipeline, including two enzyme replacement therapies for lysosomal storage disorders and two programs for life-threatening genetic conditions for which there are currently no approved treatments. The Company has assembled a team with a proven record of bringing orphan therapies to patients. Further information regarding Synageva BioPharma Corp. is available at http://www.synageva.com. About Trimeris, Inc. Trimeris, Inc. (NASDAQ: TRMS) pioneered the development of a class of antiviral drug treatments called fusion inhibitors. Trimeris’ currently marketed product is FUZEON, an anti-HIV fusion inhibitor which was developed by Trimeris in collaboration with Roche. Substantially all of Trimeris' revenues are derived from its collaboration with Roche relating to FUZEON. For more information about Trimeris, please visit the company's website at http://www.trimeris.com. Important Merger Information and Additional Information and Where to Find It This press release does not constitute an offer to sell or the solicitation of an offer to buy any securities of Trimeris or Synageva or the solicitation of any vote or approval. In connection with the proposed merger, Trimeris filed a Registration Statement on Form S-4, filed with the SEC on July 13, 2011 (the “Registration Statement”), which includes a preliminary joint proxy statement of Trimeris and Synageva and constitutes a preliminary prospectus of Trimeris. These materials are not yet final and will be further amended. The joint proxy statement/prospectus of Trimeris and Synageva will be mailed to the stockholders of Trimeris and Synageva once it is final. Investors are strongly urged to read the definitive joint proxy statement/prospectus when it becomes available and other documents filed with the SEC by Trimeris, because they will contain important information about Trimeris, Synageva and the proposed merger. Investors and security holders of Trimeris may obtain free copies of the joint proxy statement/prospectus for the proposed merger and other documents filed with the SEC by Trimeris through the website maintained by the SEC at www.sec.gov. In addition, investors and security holders of Trimeris will be able to obtain free copies of the joint proxy statement/prospectus for the proposed merger by contacting Trimeris, Inc., Attn: James Thomas, Chief Financial Officer. Investors and security holders of Synageva will be able to obtain free copies of the joint proxy statement/prospectus for the merger by contacting Synageva BioPharma Corp., Attn: Secretary, 128 Spring Street, Suite 520, Lexington, MA 02421. Trimeris and Synageva, and their respective directors and certain of their executive officers, may be deemed to be participants in the solicitation of proxies in respect of the transactions contemplated by the agreement between Trimeris and Synageva. Information regarding Trimeris’ directors and executive officers is contained in Trimeris’ Annual Report on Form 10-K for the fiscal year ended December 31, 2010, which was filed with the SEC on March 14, 2011, and in its proxy statement prepared in connection with its 2010 Annual Meeting of Stockholders, which was filed with the SEC on March 16, 2010. Information regarding Synageva’s directors and officers and a more complete description of the interests of Trimeris’ directors and officers in the proposed transaction is available in the Registration Statement.