OPKO Health, Inc. (NYSE: OPK), has completed patient enrollment in the third phase 3 trial of RAYALDEE. This trial is designed to evaluate the product’s long-term safety and efficacy in treating secondary hyperparathyroidism (SHPT) in patients with stage 3 or 4 chronic kidney disease (CKD) and vitamin D insufficiency.
This third phase 3 trial is a 6-month open-label extension of two ongoing and identical randomized, double-blind, placebo-controlled, multi-site pivotal phase 3 studies for RAYALDEE intended to support marketing approval in the United States (US). Together, the two pivotal trials involve approximately 430 patients recruited at approximately 90 US sites who are receiving six months of treatment with either RAYALDEE or placebo. Both trials will end in July 2014 and the Company expects to announce top-line data during the third quarter of 2014. In the open-label extension study, patients either continue RAYALDEE treatment or switch to RAYALDEE from placebo treatment. Additional patients will be allowed to enroll in the open-label extension study through July as they exit the blinded pivotal trials. The endpoints of all three phase 3 studies include vitamin D status and changes in plasma intact parathyroid hormone (PTH), serum calcium and serum phosphorus.
Recently, OPKO also completed a pharmacokinetic study of RAYALDEE in approximately 50 healthy US volunteers. This study, designed to evaluate the effect of food on the intestinal absorption of RAYALDEE, is the last clinical trial (aside from the above-mentioned phase 3 trials) needed to support the forthcoming New Drug Application (NDA). OPKO expects that an NDA for RAYALDEE will be filed with the US Food and Drug Administration in the first quarter of 2015.
“The development of RAYALDEE is proceeding fully as we expected: on schedule and on budget,” remarked Phillip Frost, M.D., OPKO's CEO and Chairman. “We believe our proprietary first-in-class vitamin D product will be a valuable new treatment for chronic kidney disease patients and we look forward to reporting final data from the ongoing pivotal trials promptly.”About RAYALDEE RAYALDEE is a first-in-class oral vitamin D prohormone treatment being developed for SHPT in patients with stage 3 or 4 CKD and vitamin D insufficiency. It has a proprietary modified-release formulation designed to gradually and reliably raise serum total 25-hydroxyvitamin D (prohormone) concentrations to targeted levels (at least 30 ng/mL) while avoiding upregulation of CYP24, a cytochrome P-450 enzyme that reduces the PTH-lowering potency of current vitamin D supplements. Activation of calcifediol, the active ingredient in RAYALDEE, by the kidney is tightly regulated, preventing excessive elevation of serum calcium and related side effects which limit the value of current vitamin D hormone therapies by promoting vascular and renal calcification. RAYALDEE is expected to address the approximately 4 million patients in the US, and many more elsewhere, with stage 3 or 4 CKD, SHPT and vitamin D insufficiency. About Chronic Kidney Disease CKD is a condition characterized by a progressive decline in kidney function. The kidney is normally responsible for excreting waste and excess water from the body, and for regulating various hormones. CKD is classified in five different stages — mild (stage 1) to severe (stage 5) disease — as measured by the kidney's glomerular filtration rate. According to the National Kidney Foundation, CKD afflicts over 26 million people in the US, including more than eight million patients with moderate (stages 3 or 4) and severe (stage 5) forms of CKD. In stage 5 CKD, kidney function is minimal to absent and patients require regular dialysis or a kidney transplant for survival.