APHT Aphton (MM)

Clinical Trial Demonstrates Favorable Safety Profile and Indicates Efficacy Against Disseminated Tumor Cells in Patients with Cancers of Epithelial Origin Aphton Corporation (NASDAQ:APHT) announced today the positive results from an open-label dose-escalating Phase I trial with IGN311, a humanized monoclonal antibody targeting the Lewis Y tumor-associated antigen. Lewis Y is a factor known to be over-expressed in up to 90% of epithelial carcinomas, including breast, colon, gastric and pancreatic cancers. IGN311 is being developed as a potential new therapy for the treatment of Lewis Y positive tumors. In this Phase I trial, IGN311 demonstrated favorable safety and tolerability, and advantageous pharmacokinetics with a serum half-life of more than 20 days. Data from the trial also indicate efficacy of IGN311 against Lewis Y-positive tumor cells circulating in peripheral blood: the number of such cells was significantly decreased in those patients that presented with detectable levels of such cells prior to first infusion. Twelve patients with epithelial cancers (breast, colorectal, gastric and pancreatic) were enrolled. All patients received intravenous infusions of IGN311, which was given in escalating doses, of which 3 patients received 50mg, 3 patients received 100mg and the remaining 6 patients received 200mg. IGN311 was administered on the first and fifteenth days of the study. No adverse events related to study medication were seen in the 50mg and 100mg cohort, and only one adverse event (vomiting, nausea) was observed in the 200mg arm. The antibody was generally well tolerated and hematological toxicities were not observed. Complement dependent cytotoxicity (CDC), or the capacity of the antibody to destroy tumor cells, was significantly induced by IGN311 infusions, and was correlated with IGN311 concentration in blood. "We are quite pleased with both the favorable safety profile and the antitumor activity demonstrated in this study. These results provide us with confidence as we initiate new studies with the compound," said Patrick Mooney, MD, President and Chief Executive Officer of Aphton Corporation. About IGN311 IGN311 is a humanized monoclonal antibody against the Lewis Y carbohydrate antigen, a blood group related oligosaccharide. Lewis Y is over-expressed in up to 90% of all epithelial cancers and its expression on adult normal tissues is very restricted; hence IGN311 has the potential to target a broad range of carcinomas. IGN311 is designed to exert clinical effects by destruction of tumor cells by activation of effector functions and by selective growth inhibition via functional receptors. Strategic Pipeline Aphton continues to focus its efforts on broadening and making progress in its research and development pipeline. An important component of our product portfolio is IGN101, a cancer vaccine designed to induce an immune response against EpCAM positive tumor cells, and IGN311. Aphton also has a diverse pipeline of pre-clinical and clinical products including active and passive immunotherapies. Aphton believes that immunotherapies may have certain advantages over other targeted therapies by including specificity that may lead to better efficacy and decreased toxicities for patients. 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 is currently seeking partners that will support the further development of Insegia (G17DT immunogen), its immunogen targeting the hormone gastrin. Aphton has strategic alliances with sanofi-aventis for the development and commercialization of Insegia related to cancers of the gastrointestinal system and other cancers in North America and Europe; Daiichi Pure Chemicals for the development, manufacturing and commercialization of gastrin-related diagnostic kits; and Xoma for treating gastrointestinal and other gastrin-sensitive cancers using anti-gastrin monoclonal and other antibodies. For more information about Aphton or its programs please visit Aphton's website at http://www.aphton.com. Safe Harbor This press release includes forward-looking statements, including statements about: (1) the development of IGN311 as a potential new therapy for the treatment of Lewis Y positive tumors; (2) Aphton's intent to enter into new studies with IGN311; (3) the potential of IGN311 to target a broad range of carcinomas and exert clinical effects by destruction of tumor cells; (4) Aphton's belief regarding the strength of Igeneon's product portfolio and such portfolio's ability to complement Aphton's product portfolio; (5) Aphton's intent to broaden and progress its research and development pipeline; (6) Aphton's belief that immunotherapies have certain advantages over targeted therapies; and (7) Aphton's intent to continue to seek, and its ability to find, a viable partner to financially support the further development of 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 fund the further development of its research and development programs; (2) Aphton's ability to successfully identify and consummate opportunities to broaden and progress its research and development pipeline;, (3) scientific developments regarding immunotherapies; (4) Aphton's ability to successfully integrate Igeneon's operations and product portfolio with Aphton's operations and product portfolio; (5) the actual design, results and timing of preclinical and clinical studies for Aphton's products and product candidates; (6) the ability of Aphton to develop and initiate additional clinical trials of IGN 311 and the future results of IGN 311 in the subsequent clinical trials.