Aphton Reports Efficacy of Gonadimmune for Treatment of Breast Cancer at Meeting of American Association of Cancer Research.

WOODLAND, Calif.--(BUSINESS WIRE)--April 25, 1996--Aphton reported the results of a series of experiments demonstrating the efficacy of its product Gonadimmune(TM) in treatment of breast cancer.

The report was made at the American Association of Cancer Research (AACR) meeting held on April 24 in Washington, D.C., by scientists from the University of Nottingham, the City Hospital at Nottingham and Aphton Corp.

The experiments were carried out on a large number of immunodeficient animals which were implanted with a human-derived breast cancer. Results showed that anti-Gonadimmune(TM) antibodies caused a marked inhibition of tumor growth and a tripling of survival period, compared to placebo-treated animals. When compared with agents currently used in anti-endocrine therapy of breast cancer, treatment with anti-Gonadimmune antibodies was at least as potent as tamoxifen, and anti-estrogen, and decapeptyl, a GnRH analog. The scientists noted that when applied to therapy in humans, Gonadimmune will not have the endometrial cancer and other risks of tamoxifen, but will have the significant advantage of providing a much longer-lasting response than tamoxifen or decapeptyl. Effective levels of antibodies with Gonadimmune are maintained for a minimum of six months, before a booster injection is given.

Gonadimmune is Aphton's proprietary immunogen which induces antibodies that neutralize (block) the gonadotropin-releasing hormone GnRH (which is also referred to as LHRH, luteinizing hormone releasing hormone). This is a "master hormone" that regulates the production of steroid hormones, namely, estrogen and progesterone in females, and testosterone in males. This vaccine-like product was developed by Aphton to provide hormonal therapy for cancers which are dependent on the steroid hormones. Hormonal therapy has been shown to be efficacious in humans for both breast cancer and prostrate cancer over many years.

Aphton Corp. is a biopharmaceutical company developing products using its innovative vaccine-like technology for neutralizing hormones that participate in diseases, both malignant and non-malignant, in (a) the gastrointestinal system and (b) the reproductive system. These diseases include: (a) Gastroesophageal Reflux Disease (GERD), ulcers and colorectal, stomach and pancreatic cancers; (b) endometriosis and prostate, breast and endometrial cancers. In addition, Aphton has exclusive worldwide manufacturing, distribution and sales rights for an immunocontraceptive product, also utilizing vaccine-like technology, which is now in a Phase II clinical trail funded by the World Health Organization (WHO).

CONTACT: Aphton Corp.

J.L. Whitmore, 305/374-6717