NEW YORK, Dec. 18, 2013 (GLOBE NEWSWIRE) -- Keryx Biopharmaceuticals, Inc. (Nasdaq:KERX) announced today that the U.S. Patent and Trademark Office has issued U.S. Patent No. 8,609,896. The patent, which expires in 2024, claims orally administrable forms of Zerenex prepared from ferric citrate having a BET active surface area greater than about 16 sq. m/g. The active pharmaceutical ingredient (API) of Zerenex is ferric citrate having a BET surface area substantially above this surface area threshold. This newly issued patent further enhances the Company's key patent family, which includes U.S. Patent Nos. 7,767,851, 8,299,298 and 8,338,642. These U.S. patents expire in 2024, without patent term extension, and contain composition and method of use claims covering Zerenex. Ron Bentsur, Chief Executive Officer of Keryx, commented, "We believe that our portfolio of patents will provide market exclusivity for Zerenex through at least 2024, as the high API surface area of our ferric citrate is essential for Zerenex' activity and dissolution. The patent issued today enhances our IP portfolio through the protection of orally administrable forms of Zerenex." Mr. Bentsur continued, "We are committed to protecting the long-term market potential for Zerenex through the strengthening of the patent portfolio and we believe that the issued patent today is another significant achievement toward this objective." The Company continues to prosecute additional patent applications for Zerenex, which, if issued, would expand the scope of patent claims covering Zerenex beyond 2030. The Company's New Drug Application for Zerenex is currently under review by the Food and Drug Administration with an assigned Prescription Drug User Fee Act (PDUFA) goal date of June 7, 2014. About Keryx Biopharmaceuticals, Inc. Keryx Biopharmaceuticals is focused on the acquisition, development and commercialization of medically important pharmaceutical products for the treatment of renal disease. Keryx is developing Zerenex (ferric citrate coordination complex), an oral, ferric iron-based compound. Keryx has completed a U.S.-based Phase 3 clinical program for Zerenex for the treatment of hyperphosphatemia (elevated phosphate levels) in patients with chronic kidney disease on dialysis, conducted pursuant to a Special Protocol Assessment (SPA) agreement with the Food and Drug Administration (FDA). The Company's New Drug Application (NDA) is currently under review by the FDA with an assigned Prescription Drug User Fee Act (PDUFA) goal date of June 7, 2014. The Marketing Authorization Application filing with the European Medicines Agency (EMA) is pending. The Company is also developing Zerenex in the U.S. for the management of elevated phosphorus and iron deficiency anemia in patients with Stage 3 to 5 non-dialysis dependent chronic kidney disease. In addition, Keryx's Japanese partner, Japan Tobacco Inc. and Torii Pharmaceutical Co., Ltd. has filed its New Drug Application for marketing approval of ferric citrate in Japan for the treatment of hyperphosphatemia in patients with chronic kidney disease. Keryx is headquartered in New York City.