Keryx's Zerenex meets hyperphosphatemia endpoint

Keryx Biopharmaceuticals Inc. (NASDAQ:KERX) said once-daily Zerenex ferric citrate met the primary endpoint in an open-label Phase III trial to treat hyperphosphatemia in patients with end-stage renal disease (ESRD). The oral iron-based phosphate binder demonstrated a significant dose response in the change in mean serum phosphorus from baseline to day 28. Specifically, 6 and 8 g/day Zerenex significantly reduced mean serum phosphorus from baseline to day 28 by 1.9 and 2.2 mg/dL, respectively, vs. a gain of 0.1 mg/dL from baseline for the 1 g/day Zerenex dose (p<0.0001 for both compared to baseline and p<0.0001 for both compared to the 1 g/day dose).

Zerenex led to a significant dose response reduction in calcium-phosphorous product. Furthermore, there was no clinically meaningful change in serum calcium levels observed. Keryx said high levels of serum calcium and calcium-phosphorus product are believed to be drawbacks from the some of the currently marketed phosphate binders. Phosphate binders on the market include: Fosrenol lanthanum carbonate from Shire plc (LSE:SHP; NASDAQ:SHPGY); Renvela sevelamer carbonate from Genzyme Corp. (NASDAQ:GENZ); and PhosLo calcium acetate from Fresenius SE (Xetra:FRE). ...