Peregrine Pharmaceuticals, Inc. (Nasdaq: PPHMD) today announced that the U.S. Patent and Trademark Office has issued U.S. Patent Number 7,611,704, which includes broad claims covering anti-viral uses of phosphatidylserine (PS)-targeting antibodies including Peregrine's lead clinical compound, bavituximab. PS is a unique marker exposed on the surface of virally infected cells that can be targeted to treat a broad spectrum of virus infections.
The new patent covers compositions and methods of treating virus infections using bavituximab and similar antibodies, either alone or as immunoconjugates attached to anti-viral agents, as well as in combination with other anti-viral agents. The breadth of the claims in the new patent is especially noteworthy since it includes methods for treating all viruses in humans and in animals. The therapeutic potential of these antibodies is supported by data in a landmark study published in the December 2008 edition of Nature Medicine showing that bavituximab and other PS-targeting antibodies have the potential to cure lethal virus infections across a broad range of virus families in animal disease models.
"This broad anti-viral patent further expands our intellectual property leadership in the field of PS-targeting antibodies at a time when our anti-viral program is experiencing a rising tide of interest and activity," said Steven W. King, president and CEO of Peregrine. "We are especially pleased at the scope of the issued claims in this new patent, which covers the use of bavituximab and similar antibodies in the treatment of any and all virus infections. Antibodies falling under the scope of this new patent have already demonstrated promising anti-viral activity in clinical trials in patients with hepatitis C virus (HCV) infection and are the focus of our ongoing research funded by a Transformational Medical Technologies Initiative contract to study the potential of these agents as broad spectrum viral hemorrhagic fever therapeutics."
PS, a lipid molecule normally found only on the inside of cell membranes, becomes exposed on the outside of the membranes of viruses and virally infected cells. A rapidly growing body of published scientific research confirms that exposed PS is directly involved in the pathogenesis of many serious infectious diseases. Exposed PS enables viruses to evade immune recognition and dampens the body's normal responses to infection. By masking the exposed PS, PS-targeting antibodies are believed to block these effects, allowing the body to develop a robust immune response to the pathogen.