2021 Press/Media Releases:

OPKO Health Announces Topline Results from Phase 2 Trial Evaluating RAYALDEE to Treat Symptomatic COVID-19 Outpatients

Preliminary data indicate that improving vitamin D status with oral RAYALDEE results in earlier resolution of respiratory symptoms associated with COVID-19  

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MIAMI, Dec. 23, 2021 (GLOBE NEWSWIRE) -- OPKO Health, Inc. (NASDAQ: OPK) announces preliminary topline results from its Phase 2 trial with RAYALDEE® to treat mild.to-moderate COVID-19. This study builds on increasing medical evidence that vitamin D repletion therapy can mitigate the severity of upper respiratory tract infections and accelerate recovery from COVID-19.

RAYALDEE, after oral administration, gradually releases calcifediol, the natural storage form of vitamin D3, to safely and reliably raise a patient’s serum total 25-hydroxyvitamin D (25D) well above current targets of 20 or 30 ng/mL. RAYALDEE is approved in the U.S. and many European countries for treating secondary hyperparathyroidism in non-dialysis chronic kidney disease (CKD) patients by raising 25D to levels as high as 100 ng/mL.

In the Phase 2 trial, titled “A Randomized, Double-Blind Placebo-Controlled Study to Evaluate the Safety and Efficacy of RAYALDEE (calcifediol) Extended-release Capsules to Treat Symptomatic Patients Infected with SARS-CoV-2 (REsCue),” 171 symptomatic COVID-19 outpatients were enrolled from multiple U.S. sites and randomized in a 1:1 ratio for 4 weeks of treatment with RAYALDEE or placebo and a 2-week follow-up. Dosing with RAYALDEE was designed to progressively raise serum 25D to 50 to 100 ng/mL by Day 7, beginning with 300 mcg on Days 1, 2 and 3 followed by 60 mcg per day on Days 4 through 27. COVID-19 symptoms were self-reported daily during the 42-day study using the FLU-PRO Plus© questionnaire, an outcome tool validated for upper respiratory tract infections. Blood samples and safety assessments were obtained at 7-day intervals.

One primary efficacy endpoint was reaching the targeted serum 25D level. By Day 7, mean serum 25D levels increased with RAYALDEE treatment to 82 ng/mL (p<0.001) and remained elevated for the duration of the trial, with 88% of subjects attaining the targeted level. In contrast, mean 25D declined slightly with placebo treatment.

A second primary efficacy endpoint was the benefit of raising serum 25D on the time to resolution of five COVID-19 symptoms: trouble breathing, chest congestion, dry or hacking cough, body aches and pains, and chills and shivering. The three symptoms related to respiratory function, evaluated together, resolved more quickly when serum 25D was elevated at Days 7 and 14 (Wilcoxon p<0.05), with resolution of chest congestion occurring 3.4 days sooner (Wilcoxon p<0.05). In subjects achieving increases in serum 25D of at least 25 ng/mL, chest congestion resolution occurred 4 days earlier (Wilcoxon p< 0.05). The mean time to resolution for all five symptoms considered in aggregate was not significantly different between the treatment groups since symptoms unrelated to respiratory function were unresponsive to treatment.

The average age of enrolled subjects was 43; 57% were female, 93% White, 6% African.American,1% Other. Nearly 40% were obese and 79% overweight, based on body mass index (BMI) greater than 30 or 25, respectively. Approximately 30% had comorbidities, most commonly hypertension.

Safety endpoints included vital signs, physical examinations, adverse events, electrocardiograms and biochemical assessments, all of which showed no meaningful changes with treatment.  


RAYALDEE is an extended-release oral formulation of calcifediol, a prohormone of calcitriol, the active form of vitamin D3. The product is the first and only medicine approved by the U.S. Food and Drug Administration (FDA) for raising serum total 25D and lowering blood levels of intact parathyroid hormone (iPTH). RAYALDEE, approved to treat secondary hyperparathyroidism (SHPT) in adults with stage 3 or 4 CKD and vitamin D insufficiency, was launched in the U.S. in November 2016.

About OPKO Health, Inc.

OPKO is a multinational biopharmaceutical and diagnostics company that seeks to establish industry-leading positions in large, rapidly growing markets by leveraging its discovery, development, and commercialization expertise and novel and proprietary technologies. For more information, visit www.opko.com

LHA Investor Relations
Yvonne Briggs, 310-691-7100
Bruce Voss, 310-691-7100


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