OPKO Health, Inc. (NYSE: OPK), announced successful top-line results from the first pivotal phase 3 trial of Rayaldee™. This trial is one of two identical randomized, double-blind, placebo-controlled, multi-site studies intended to establish the safety and efficacy of Rayaldee as a new treatment for secondary hyperparathyroidism (SHPT) in patients with stage 3 or 4 chronic kidney disease (CKD) and vitamin D insufficiency. Both trials are the subject of a Special Protocol Assessment (SPA) established with the United States (U.S.) Food and Drug Administration (FDA) in August 2012.
“Top-line data from this study demonstrate that Rayaldee effectively controls secondary hyperparathyroidism in patients with stage 3 or 4 chronic kidney disease by correcting vitamin D insufficiency,” stated Joel Z. Melnick, MD, Vice President of Clinical Research and Development for OPKO’s Renal Division. “Rayaldee was equally effective in both disease stages, indicating that this new therapy is appropriate even for patients with minimal functioning kidney mass.”
This trial involved 213 adult patients recruited from 39 sites throughout the U.S. Patients were stratified by CKD stage and randomized in a 2:1 fashion to receive six months of treatment with either Rayaldee or placebo. On enrollment, all patients exhibited vitamin D insufficiency which was corrected in 96% of patients treated with Rayaldee.
The completed trial successfully met all primary efficacy and safety endpoints. The primary efficacy endpoint was a responder analysis in which “responder” was defined as any treated subject who demonstrated an average 30% decrease in plasma parathyroid hormone (PTH) from pre-treatment baseline during the last six weeks of the treatment period. A significantly higher response rate (p<0.001) was observed with Rayaldee which steadily increased with treatment duration. The response rate with Rayaldee was similar in CKD stages 3 and 4. Safety and tolerability data were comparable in both treatment groups.
“Rayaldee is designed to fill a void in the treatment armamentarium of nephrologists and endocrinologists who care for pre-dialysis chronic kidney disease patients,” commented Dr. Charles W. Bishop, CEO of OPKO’s Renal Division. “Controlled trials have shown that over-the-counter and prescription vitamin D supplements are ineffective in treating SHPT in these patients and are, at best, unreliable in correcting vitamin D insufficiency. On the other hand, vitamin D hormone drugs can effectively treat SHPT but, due to high potency, often oversuppress PTH, increasing the risk of adynamic bone disease and vascular calcification. These hormone drugs are entirely ineffective in treating vitamin D insufficiency, the underlying cause of SHPT in most pre-dialysis patients. Rayaldee addresses a long-standing unmet need to safely control SHPT by reliably correcting vitamin D insufficiency.”