Aphton Corporation Announces Mutual Agreement To Dissolve Co-Promotion And Licensing Agreement Related To Anti-Cancer Product Insegia(TM) With Sanofi Pasteur

PHILADELPHIA--(BUSINESS WIRE)--Nov. 9, 2005--Aphton Corporation (NASDAQ:APHT - News) announced today that it has entered into a mutual decision and agreement to terminate the co-promotion and licensing agreement with sanofi pasteur related to Aphton's lead immunotherapy compound, Insegia(TM) (G17DT immunogen). The agreements related to the co-promotion, licensing and supply of Insegia will be terminated effective immediately.

The original agreements, signed in 1997, were related to the development, manufacturing and co-promotion rights for all human cancer applications of Insegia, including stomach, esophageal, colorectal, and pancreatic cancers. Under the terms of the agreement, Aphton was to be responsible for product development, clinical trials and regulatory filings, and sanofi pasteur was to be responsible for the promotion, advertising, marketing, distribution and sales of Aphton's anti-gastrin vaccine in North America and Europe. In addition, Aphton and sanofi pasteur had entered into agreements providing for the supply of diphtheria toxoid, a key component of Insegia.

"By dissolving these agreements and regaining essentially unencumbered worldwide rights to Insegia we are in a better position to find a new corporate partner with the goal of furthering the development of Insegia, specifically as a therapeutic option for patients with gastric cancer. Up until this point any discussions we have had with potential partners have been limited," commented Patrick Mooney, MD, Chairman and Chief Executive Officer of Aphton. "We continue to be encouraged by the survival data seen in patients who did achieve an antibody response in our clinical trials with Insegia. We believe that this data combined with a much broader licensing opportunity will draw significant interest from potential partners."

Additional details related to the dissolution of the co-promotion and licensing agreement will be contained in Aphton's Form 8-K, filed with the Securities and Exchange Commission.

The Company will be holding a conference call on Thursday, November 10, 2005 at 9:00 a.m. ET to discuss the mutual dissolution of the co-promotion and licensing agreement as well as other items related to the Company.

A live audio webcast of the conference call can be accessed either by telephone at:

Toll Free in the US/Canada at 1-800-322-0079; Code Aphton Corporation Outside the U.S. at 1-973-409-9258; Code Aphton Corporation

Or via the internet at http://viavid.net/dce.aspx?sid=00002AC7.

A replay of the presentation will be available via the website and will begin approximately 2 hours after the conference call has concluded and will be available for 14 days.

About Aphton

Aphton Corporation, headquartered in Philadelphia, Pennsylvania, is a clinical stage biopharmaceutical company focused on developing targeted immunotherapies for cancer. Aphton's products seek to empower the body's own immune system to fight disease. Through the acquisition of Igeneon AG in March 2005, Aphton acquired late-stage products, IGN101, a cancer vaccine designed to induce an immune response against EpCAM-positive tumor cells, and IGN311, a fully humanized antibody against the Lewis Y antigen. Aphton has strategic alliances with Xoma for treating gastrointestinal and other gastrin-sensitive cancers using anti-gastrin monoclonal and other antibodies; and with Daiichi Pure Chemicals for the development, manufacturing and commercialization of gastrin-related diagnostic kits. Aphton's most advanced product, Insegia(TM), targets the hormone, gastrin 17, in an attempt to treat gastrointestinal cancers. For more information about Aphton or its programs please visit Aphton's website at www.aphton.com.

Safe Harbor

This press release includes forward-looking statements, including statements about: (1) the Company's belief that as a result of the dissolution of its strategic alliance with sanofi pasteur, it is in a better position to find a new corporate partner with the goal of further developing Insegia, particularly in gastric cancer patients; (2) the Company's belief that the dissolution of Insegia will result in a broader licensing opportunity; (3) the Company's belief that the activity demonstrated by Insegia, together with the broader licensing opportunity, will enhance the Company's ability to find a partner as enthusiastic as the Company to financially support the further development of Insegia; (4) the Company's belief in gastrin as a viable target in treating cancer; and (5) the Company's expectation regarding the purpose and effectiveness of fully-humanized monoclonal antibodies, IGN101 and IGN311, and its cancer immunotherapy, Insegia. These forward-looking statements may be affected by the risks and uncertainties inherent in the drug development process and in Aphton's business. This information is qualified in its entirety by cautionary statements and risk factor disclosure contained in Aphton's Securities and Exchange Commission filings, including Aphton's report on Form 10-K filed with the Commission on March 16, 2005. Aphton wishes to caution readers that certain important factors may have affected and could in the future affect Aphton's beliefs and expectations and could cause the actual results to differ materially from those expressed in any forward-looking statement made by or on behalf of Aphton. These risk factors include, but are not limited to: (1) Aphton's ability to find a corporate partner who is as enthusiastic about Insegia as the Company and who is capable of financially supporting the further development of Insegia, particularly in gastric cancer patients; (2) Aphton's ability to fund the further development of its research and development program; (3) Aphton's ability to successfully identify and consummate opportunities to broaden and progress its research and development pipeline; (4) scientific developments regarding immunotherapy; (5) Aphton's ability to successfully integrate Igeneon's operations and product portfolio with Aphton's operations and product portfolio; and (6) the actual design, results and timing of preclinical and clinical studies for both companies' products and product candidates.

Contact: For Aphton Corporation, Philadelphia TS Communications Group, LLC Tara Spiess, 215-218-4371 ir@aphton.com

Source: Aphton Corporation