NEW YORK, Nov. 8, 2013 (GLOBE NEWSWIRE) -- Keryx Biopharmaceuticals, Inc. (Nasdaq:KERX) today announced preliminary, unaudited data from an ongoing 48-week safety extension study of Zerenex™ (ferric citrate coordination complex) the Company's drug candidate for the treatment of hyperphosphatemia in patients with chronic kidney disease on dialysis. Only patients who had participated in, and successfully completed the 58-week, long-term Phase 3 study were eligible for enrollment into this safety extension study. This 48-week, open-label extension (OLE) study, which is not a regulatory requirement, is being conducted in 35 sites in the United States. The study commenced enrollment in August 2012 and is anticipated to be completed in the first half of 2014.
Patients in the OLE study are titrated to achieve and maintain normal serum phosphorus levels (3.5 to 5.5 mg/dL) for a period of 48 weeks. This study, together with the 58-week, long-term Phase 3 safety and efficacy study, represents potential cumulative exposure to Zerenex of up to 2 years.
Enrollment in the OLE study included 168 patients, of which 166 patients were dosed with Zerenex, consisting of 114 and 52 patients from the Zerenex and Active Control arms of the completed long-term Phase 3 study, respectively.The data presented is through October 31, 2013, and appear to corroborate the data observed in the completed long-term Phase 3 study. Key highlights from this preliminary data include:
- Effective control of serum phosphorus within the normal range of 3.5 to 5.5 mg/dL;
- Increase and plateau of transferrin saturation (TSAT) and ferritin at weeks 12 and 24, respectively, with ferritins decreasing after week 36;
- Extremely limited use of intravenous (IV) iron in the study, with 69% of patients not receiving any IV iron throughout the study; and
- Substantially lower use of IV iron and erythropoiesis stimulating agents (ESAs) in the OLE study, as compared to national averages, by 85% and 62%, respectively, while maintaining hemoglobin.
|Baseline||Week 12||Week 24||Week 36||Week 48|
|Number of subjects at timepoint as of October 31, 2013||166||154||135||108||59|
|Serum phosphorus (mg/dL)||5.7||5.3||5.3||5.2||5.5|