Keryx Finally Succeeds With a Clinical Trial, for Kidney Disease Drug

It looks like a Hail Mary pass came through for Keryx Biopharmaceuticals (NASDAQ: [[ticker:KERX]]). In the past few years, both of New York-based Keryx’s top drug candidates failed key clinical trials, leaving the company to bet all its fortunes on its one remaining drug, meant for kidney dialysis patients. Today Keryx reported that the drug, ferric citrate (Zerenex), met both its primary and secondary goals in a Phase III clinical trial.

The news sent Keryx shares soaring by more than 80 percent by midday to $6.19.

Ferric citrate belongs to a class of drugs called phosphate binders, used to remove dangerously elevated levels of phosphate from the blood of people suffering from chronic renal failure. Keryx said initial top-line results from the study showed that ferric citrate produced a “highly statistically significant change” in reducing serum phosphate levels in dialysis patients, when compared with placebo. The drug also increased iron stores for those patients, thus reducing dependence on intravenous iron replacement and erythropoiesis-stimulating agents such as Amgen’s Epogen.

As a result, the company said it will submit applications for approval with the Food & Drug Administration and the European Medicines Agency in the second quarter of this year. If approved, ferric citrate will go up against the market-leading phosphate binders Renagel and Renvela, both made by Sanofi’s (NYSE: [[ticker:SNY]]) subsidiary, Genzyme. Renvela will go off patent in 2014, but Keryx CEO Ron Bentsur told investors on a conference call this morning that ferric citrate would still offer significant cost savings, because patients would be able to reduce their use of intravenous iron and EPO. The market for phosphate binders to treat end-stage renal disease patients is almost $1.5 billion worldwide, Keryx said.

The company’s 52-week trial enrolled 441 patients in end-stage renal disease, divided between Keryx’s drug and placebo. The full data from the trial will be presented at a future medical meeting, the company said.

As Xconomy reported in May 2012, Keryx’s stock fell 65 percent to $1.74 last April after the company announced that a late-stage trial of its colon cancer drug perifosine failed. That was preceded by an 81 percent one-day plunge in March 2008, when Keryx reported that its then-lead product, a drug to treat diabetic neuropathy, failed in a late-stage trial. By May of last year Bentsur admitted to Xconomy that his company was “deep in the penalty box” (to continue the sports metaphors). Keryx was founded in 1997, and in 2005 it licensed ferric citrate from Taiwan-based Panion & BF Biotech.

Author: Catherine Arnst

Catherine Arnst is an award- winning writer and editor specializing in science and medicine. Catherine was Senior Writer for medicine at BusinessWeek for 13 years, where she wrote numerous cover stories and wrote extensively for the magazine’s website, including contributing to two blogs. She followed a broad range of issues affecting medicine and health and held primary responsibility for covering the battle in Washington over health care reform. Catherine has also written for the Boston Globe, U.S. News & World Report and The Daily Beast, and was Director of Content Development for the health practice at Edelman Public Relations for two years. Prior to joining BusinessWeek she was the London-based European Science Correspondent for Reuters News Service. She won the 2004 Business Journalist of the Year award from London’s World Leadership Forum, and in 2003 was the first recipient of the ACE Reporter Award from the European School of Oncology for her five-year body of work on cancer. She holds a bachelor’s degree in journalism from Boston University.