(Reuters) - Keryx Biopharmaceuticals Inc said a late-stage trial of its experimental kidney disease drug met the main study goal of reducing phosphate levels in blood, sending the company's shares up 43 percent before the bell.
The level of phosphate in blood increases when kidney function declines. Keryx is testing Zerenex as a treatment for elevated serum phosphorus levels, or hyperphosphatemia, in patients with end-stage renal disease on dialysis.
The drug showed a statistically significant reduction in patients' blood phosphate level compared with a placebo over a four-week period.
Zerenex also met the two secondary goals of increasing the levels of two proteins in the blood and reducing the need for intravenous iron and erythropoiesis-stimulating agent (ESA), an agent used to stimulate red blood cell production.
The company expects to file for regulatory approvals of the drug in the United States and Europe in the second quarter of 2013.
Zerenex, the company's only clinical candidate, is also being tested in a mid-stage study in patients with chronic kidney disease who are not dependent on dialysis.
If approved, Zerenex will compete with Renagel and Renvela, both developed by Sanofi's biotech subsidiary, Genzyme Corp.
Shire Plc's Fosrenol and Fresenius Medical Care's PhosLo also claim market share for the same indication.
Shares of New-York based Keryx were up about 43 percent at $4.90 before the bell. They closed at $3.43 on Friday on the Nasdaq.
(Reporting by Esha Dey and Pallavi Ail in Bangalore; Editing by Roshni Menon)