Keryx Biopharmaceuticals Inc's Japanese partner, Japan Tobacco Inc. (JT) and Torii Pharmaceutical Co., Ltd. (Torii), have announced positive top-line results from a phase III study of ferric citrate in Japan for the treatment of hyperphosphatemia in end-stage renal disease patients on haemodialysis. This study is part of an ongoing phase III programme for ferric citrate in Japan for the treatment of hyperphosphatemia.

The phase III study, conducted in Japan, was an open-label, randomized study evaluating the efficacy and safety of ferric citrate against an active control, sevelamer hydrochloride, over 12 weeks in hemodialysis patients with hyperphosphatemia. In the top-line results, which evaluated the change of serum phosphorus from baseline, the primary endpoint of efficacy met non-inferiority to sevelamer hydrochloride. Furthermore, there were no clinically significant findings on safety and tolerability of ferric citrate within the treatment period.

JT/Torii stated that it is aiming to submit the marketing application for ferric citrate in Japan in the fiscal year ending March 31, 2013.

Ron Bentsur, Chief Executive Officer of Keryx, said, “We congratulate our partner, JT/Torii, on their successful phase III study and we are excited by their progress. We are also encouraged about our partner's plans to file their marketing application in Japan within less than a year, similar to our expected timelines for the US NDA and European MAA filings.” Bentsur added, “We are enthusiastic about Zerenex's potential differentiated product profile and its prospects for becoming an important part of the treatment of hyperphosphatemia in dialysis patients worldwide.”

Zerenex (ferric citrate), a ferric iron-based phosphate binder, is also in a phase III clinical programme in the United States for the treatment of hyperphosphatemia (elevated phosphate levels) in patients with end-stage renal disease on dialysis, which is being conducted pursuant to a Special Protocol Assessment agreement with the FDA.

Keryx holds a worldwide licence (except for certain Asian Pacific countries) to Zerenex from Panion & BF Biotech, Inc.

In September 2007, Keryx sublicensed to JT/Torii the exclusive rights for the development and commercialization of its hyperphosphatemia drug, Zerenex (ferric citrate), in Japan. The licensing arrangement calls for JT/Torii to pay to Keryx up to $100 million in up-front license fees and payments upon the achievement of specified milestones, of which $28 million has been received by Keryx to date. In addition, upon commercialization, JT/Torii will make royalty payments to Keryx on net sales of the drug in Japan. JT/Torii are responsible for all development and commercialization costs in Japan.

Keryx Biopharmaceuticals is focused on the acquisition, development and commercialization of medically important pharmaceutical products for the treatment of renal disease and cancer.