FDA Awards $2M to Phase 2 Trial of Vitamin D for Reducing Risk of SCD Respiratory Complications

The U.S. Food and Drug Administration (FDA) has awarded $2 million to support a Phase 2 clinical trial testing whether daily supplementation of vitamin D reduces the risk of respiratory complications in children and adolescents with sickle cell disease (SCD).

Gary M. Brittenham, MD, a pediatrician and professor at Columbia University Irving Medical Center in New York, was the recipient of the four-year grant. 

The ViDAS-2 study will compare the effectiveness of a daily dose of oral vitamin D₃ (3,333 IU/day) with a monthly dose (100,000 IU/month) over two years. It is intended to determine if daily supplementation can reduce more rapidly the rate of respiratory events — including respiratory infections, asthma exacerbations, or acute chest syndrome events — and lead to improvements in pulmonary and immune function.

Brittenham and his team were involved in a prior Phase 2 trial (ViDAS-1,  NCT01443728). In 62 SCD patients aged 3-20, oral vitamin D₃ (cholecalciferol, a major form of vitamin D) given once per month reduced the annual rate of respiratory complications — a leading cause of disease and death in these patients — by more than 50%.

However, this reduction was observed only after one year of supplementation, and with no significant differences between standard (12,000 IU/month) and higher supplement doses (100,000 IU/month). Also, with monthly dosing, vitamin D3 is cleared from the circulation within days and slowly accumulates in adipose (fat) tissue.

VIDAS-2 will test a daily regimen, as researchers believe that switching to more frequent supplementation will result in more sustained increases in vitamin D3 levels in the blood, and faster anti-infective and immunomodulatory benefits. The team expects rapid increases in circulating vitamin D3 and a reduction in the rate of respiratory complications by 50% or more within the first year.

Another 11 grants, totaling more than $15 million, were awarded to investigators across the country as part of the Orphan Products Clinical Trials Grants Program, funded by the U.S. Congress to encourage  development and access to the market of therapies, medical devices and medical foods for rare diseases.

Most of the grants aim to support the development of products for rare diseases affecting children (75% of the grants), or patients with rare cancers (67%).

“For more than 35 years, the FDA has been providing much-needed financial support for clinical trials of potentially life-changing treatments for patients with rare diseases. To date, the Orphan Products Clinical Trials Grants Program’s grants have supported research that led to the marketing approval of more than 60 treatments for rare diseases,” Amy Abernethy, MD, PhD, the FDA’s principal deputy commissioner, said in a press release.

“We are encouraged by the amount of interest we continue to have in the grants program and are committed to working with researchers and industry to facilitate and support the study and development of treatments for patients with rare diseases,” she said.

Past studies funded by this program have contributed to recent product approvals, including: a first FDA-approved lipid emulsion made from fish oil as a source of calories and fatty acids for children with parenteral nutrition-associated cholestasis; and Vyndaqel (tafamidis, by Pfizer). the first treatment for heart disease caused by familial amyloid polyneuropathy.