March 18, 2003

Altor Bioscience Corp. announced that the U.S. Patent and Trademark Office (PTO) has issued a patent covering the Company's core T-cell receptor (TCR) technology. Altor's approach is to use TCR molecules, which can detect cancerous or diseased cells, to elicit immune responses or target drugs to tumors or virus-infected cells. Altor has developed a unique proprietary technology for producing biologically active, soluble TCR molecules in a single-chain format (scTCR). Altor’s new U.S. patent #6,534,633 entitled “Polyspecific binding molecules and uses thereof” covers compositions that include polyspecific molecules in which a binding domain of an antibody is linked to the scTCR. Altor is currently using this technology to develop novel drugs capable of directing immune effector cells to selectively eliminate disease-causing cells. Polyspecific scTCR molecules may also prove useful in therapies for autoimmune diseases and in diagnostic and antigen-discovery applications. With this patent, Altor has an intellectual property portfolio that includes 18 issued U.S. and foreign patents and more than 40 patent applications covering T-cell receptors and MHC molecule technologies.