The US Food and Drug Administration (FDA) has approved calcifediol (Rayaldee, Opko Health, Inc) for the treatment of adults with secondary hyperparathyroidism (SHPT) associated with vitamin D insufficiency (serum total 25-hydroxyvitamin D levels < 30 ng/mL) in stage 3 to 4 chronic kidney disease (CKD), according to a company news release.
This is the first product to receive FDA approval for this indication, according to the company.
Calcifediol is a prohormone formulated as an extended-release capsule containing 30 μg of the medication. Calcifediol raises serum total 25-hydroxyvitamin D levels and lowers elevated intact parathyroid hormone (PTH) levels. Calcifediol is not intended for use in patients with stage 5 CKD or with end-stage renal disease receiving dialysis.
"Rayaldee is an important new option for treating SHPT in patients with stage 3 or 4 CKD and vitamin D insufficiency," Kevin J. Martin, MD, director of research, Division of Nephrology, Saint Louis University School of Medicine, Missouri, said in the news release. "The great majority of SHPT cases in this patient population are associated with vitamin D insufficiency, a problem that Rayaldee can correct."
The approval follows discussion of data from two 26-week, placebo-controlled, double-blind phase 3 trials. The trials showed that a larger proportion of patients with stage 3 or 4 CKD with SHPT and vitamin D insufficiency were able to achieve 30% or greater reductions in plasma intact parathyroid hormone when treated with calcifediol compared with patients who received placebo. More than 80% of patients who received calcifediol experienced correction of vitamin D insufficiency compared with less than 7% of those who received placebo.
Mean serum calcium and phosphorous levels rose by 0.1 mg/dL in patients who received calcifediol compared with those who received placebo, but these changes were deemed clinically insignificant. The researcher observed no differences in the efficacy or safety of the treatment between patients with stage 3 or stage 4 CKD.
The most common adverse reactions (≥3% and more frequent than placebo) were anemia, nasopharyngitis, increased blood creatinine, dyspnea, cough, congestive heart failure, and constipation.
"Rayaldee fills a large void in the current treatment options for SHPT in predialysis patients," Charles W. Bishop, PhD, chief executive officer of Opko's Renal Division, said in the news release. "The current standard of care is high dose vitamin D supplementation, an approach for treating SHPT that is neither FDA approved nor demonstrated to be safe and effective in this population. SHPT is a progressive disease that becomes increasingly debilitating and difficult to treat, necessitating timely and effective treatment."
Potential adverse effects include hypercalcemia, which can also result in digitalis toxicity, and adynamic bone disease with subsequent increased fracture risk if the drug suppresses intact PTH levels to abnormally low levels. Hypercalcemia of any cause can potentiate digitalis toxicity.
Excessive administration of calcifediol can cause hypercalciuria, hypercalcemia, hyperphosphatemia, or oversuppression of intact PTH.
Vitamin D overdosage may include constipation, decreased appetite, dehydration, fatigue, irritability, muscle weakness, or vomiting.
Patients who take cytochrome P450 inhibitors, thiazides, cholestyramine, phenobarbital, or other anticonvulsants at the same time they take calcifediol may need dose adjustments and more frequent monitoring.
Rayaldee Approved by FDA for Secondary Hyperparathyroidism. Medscape. Jun 21, 2016.