Peregrine Pharmaceuticals awarded two new U.S. patents for targeted anti-aminophospholipid agents

Peregrine Pharmaceuticals, Inc. today reported the issuance of two U.S. patents that significantly broaden the company's intellectual property leadership in the field of targeted anti-aminophospholipid agents.

The new patents grant Peregrine broad anti-viral method claims using a range of phosphatidylethanolamine (PE) binding agents, including PE-binding peptides attached to anti-viral agents as well as those conjugated to antibodies or other substances.

"These are significant patents for Peregrine that substantially expand our intellectual property portfolio in the field of aminophospholipid-targeting agents," said Dr. Shelley Fussey, vice president of intellectual property at Peregrine. "These anti-PE agents appear to have anti-viral properties similar to the anti-phosphatidylserine (PS) monoclonal antibody bavituximab that we currently are testing in clinical trials in HCV patients and in preclinical studies for HIV and other viral infections. We are especially pleased at the breadth of the issued claims, which provide Peregrine with U.S. patent coverage for methods of combating all relevant viruses using the claimed anti-PE peptide conjugates, either used alone or in combination with other anti-viral drugs. As peptide conjugates, anti-PE agents may be well-suited for use in some of these broad anti-viral applications."

The science underlying the two new patents was presented in April 2008 at the 95th Annual Meeting of the American Association of Immunologists by Dr. Melina Soares of the University of Texas Southwestern Medical Center.* She presented data showing that similar to PS, the target for Peregrine's bavituximab program, the aminophospholipid PE is normally located on the inside of cell membranes, but becomes exposed on the external surface of enveloped viruses and virus-infected cells. Using a biotin-conjugated form of the peptide drug duramycin, which is known to bind to PE, Dr. Soares and her colleagues demonstrated that exposed PE could serve as a broad-spectrum target for anti-viral therapy. Specifically, they showed that duramycin linked to biotin neutralized multiple enveloped viruses and that it showed therapeutic efficacy in a lethal mouse model of cytomegalovirus.

U.S. Patent #7,378,386 issued on May 27, 2008 and U.S. Patent #7,384,909 issued on June 10, 2008.

*M. Melina Soares, Susan Mims, Gustavo Barbero, Shuzhen Li and Philip E. Thorpe, "Anti-Viral Effects of Phosphatidylethanolamine-Targeting Agents", American Association of Immunologists Annual Meeting, San Diego, California, April 7, 2008.