Aphton Announces Mutual Agreement to Dissolve Co-Promotion and Licensing Agreement Related to Anti-Cancer Product Insegia(TM) with Sanofi Pasteur

Aphton Corporation (NASDAQ:APHT) announced today that it hasentered into a mutual decision and agreement to terminate theco-promotion and licensing agreement with sanofi pasteur related toAphton's lead immunotherapy compound, Insegia(TM) (G17DT immunogen).The agreements related to the co-promotion, licensing and supply ofInsegia will be terminated effective immediately.

The original agreements, signed in 1997, were related to thedevelopment, manufacturing and co-promotion rights for all humancancer 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 trialsand regulatory filings, and sanofi pasteur was to be responsible forthe promotion, advertising, marketing, distribution and sales ofAphton's anti-gastrin vaccine in North America and Europe. Inaddition, Aphton and sanofi pasteur had entered into agreementsproviding for the supply of diphtheria toxoid, a key component ofInsegia.

"By dissolving these agreements and regaining essentiallyunencumbered worldwide rights to Insegia we are in a better positionto find a new corporate partner with the goal of furthering thedevelopment of Insegia, specifically as a therapeutic option forpatients with gastric cancer. Up until this point any discussions wehave had with potential partners have been limited," commented PatrickMooney, MD, Chairman and Chief Executive Officer of Aphton. "Wecontinue to be encouraged by the survival data seen in patients whodid achieve an antibody response in our clinical trials with Insegia.We believe that this data combined with a much broader licensingopportunity will draw significant interest from potential partners."

Additional details related to the dissolution of the co-promotionand licensing agreement will be contained in Aphton's Form 8-K, filedwith 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 ofthe co-promotion and licensing agreement as well as other itemsrelated to the Company.

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

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

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

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

About Aphton

Aphton Corporation, headquartered in Philadelphia, Pennsylvania,is a clinical stage biopharmaceutical company focused on developingtargeted immunotherapies for cancer. Aphton's products seek to empowerthe body's own immune system to fight disease. Through the acquisitionof Igeneon AG in March 2005, Aphton acquired late-stage products,IGN101, a cancer vaccine designed to induce an immune response againstEpCAM-positive tumor cells, and IGN311, a fully humanized antibodyagainst the Lewis Y antigen. Aphton has strategic alliances with Xomafor treating gastrointestinal and other gastrin-sensitive cancersusing anti-gastrin monoclonal and other antibodies; and with DaiichiPure Chemicals for the development, manufacturing andcommercialization of gastrin-related diagnostic kits. Aphton's mostadvanced product, Insegia(TM), targets the hormone, gastrin 17, in anattempt to treat gastrointestinal cancers. For more information aboutAphton or its programs please visit Aphton's website atwww.aphton.com.

Safe Harbor

This press release includes forward-looking statements, includingstatements about: (1) the Company's belief that as a result of thedissolution of its strategic alliance with sanofi pasteur, it is in abetter position to find a new corporate partner with the goal offurther developing Insegia, particularly in gastric cancer patients;(2) the Company's belief that the dissolution of Insegia will resultin a broader licensing opportunity; (3) the Company's belief that theactivity demonstrated by Insegia, together with the broader licensingopportunity, will enhance the Company's ability to find a partner asenthusiastic as the Company to financially support the furtherdevelopment of Insegia; (4) the Company's belief in gastrin as aviable target in treating cancer; and (5) the Company's expectationregarding the purpose and effectiveness of fully-humanized monoclonalantibodies, IGN101 and IGN311, and its cancer immunotherapy, Insegia.These forward-looking statements may be affected by the risks anduncertainties inherent in the drug development process and in Aphton'sbusiness. This information is qualified in its entirety by cautionarystatements and risk factor disclosure contained in Aphton's Securitiesand Exchange Commission filings, including Aphton's report on Form10-K filed with the Commission on March 16, 2005. Aphton wishes tocaution readers that certain important factors may have affected andcould in the future affect Aphton's beliefs and expectations and couldcause the actual results to differ materially from those expressed inany forward-looking statement made by or on behalf of Aphton. Theserisk factors include, but are not limited to: (1) Aphton's ability tofind a corporate partner who is as enthusiastic about Insegia as theCompany and who is capable of financially supporting the furtherdevelopment of Insegia, particularly in gastric cancer patients; (2)Aphton's ability to fund the further development of its research anddevelopment program; (3) Aphton's ability to successfully identify andconsummate opportunities to broaden and progress its research anddevelopment pipeline; (4) scientific developments regardingimmunotherapy; (5) Aphton's ability to successfully integrateIgeneon's operations and product portfolio with Aphton's operationsand product portfolio; and (6) the actual design, results and timingof preclinical and clinical studies for both companies' products andproduct candidates.