New U.S. patent covers key element of Xencor's Xtend half-life prolongation technology

Xencor, Inc., a company using its proprietary Protein Design Automation® (PDA) platform technology to engineer next-generation antibodies, announced today that the U.S. Patent and Trademark Office has issued Xencor a broad patent covering optimized monoclonal antibody variants and their application for extending in vivo half-life of  antibodies. U.S. Patent 8,088,376 is the latest in Xencor's expanding portfolio of patents covering antibody drug candidates and engineering technology to impart specific therapeutic properties, including antibody-dependent cell cytotoxicity (ADCC), immunomodulation and increased half-life and efficacy.

"The issuance of this new patent covers the key element of Xencor's Xtend™ half-life prolongation technology and supports the work we are doing in collaboration with pharmaceutical industry partners to incorporate this technology in multiple drug candidates and to develop biosuperior versions of approved antibodies," said Bassil Dahiyat, Ph.D., president and CEO of Xencor. "Our PDA technology platform has enabled Xencor to develop an extensive pipeline of clinical-stage products, and our strong patent portfolio positions the company to be a leader in the development of best-in-class antibody therapeutics."

The patent covers amino acid modifications in the Fc domain, part of the constant region of antibodies that improves serum half-life by 2 to 3 fold over native antibodies. Longer half-lives allows for reduced dosing frequency, lower dosing, and potentially improved tolerability and efficacy.

Xencor's intellectual property portfolio now consists of 47 U.S. and 36 foreign issued patents and numerous pending patents for protein and antibody engineering.