High dose cholecalciferol (vitamin D3) oil as add-on therapy in subjects with relapsing-remitting multiple sclerosis (RRMS) receiving subcutaneous interferon β-1a (scIFNβ-1a) (S44.005)

Objective: The SOLAR study (NCT01285401) investigated the effects of vitamin D₃ (cholecalciferol) as add-on to scIFN β-1a.

Background: The role of vitamin D supplementation in MS disease progression remains uncertain.

Design/Methods: A prospective, randomized, double-blind, multicenter, 48-week study. Patients with RRMS and 25-hydroxyvitamin D serum concentration ≤150 nmol/L were randomized to 44 μg scIFNβ-1a tiw plus either cholecalciferol (14,007 IU [350 μg]) or placebo. Primary endpoint: % subjects disease activity free (DAF) at Week 48, defined as the absence of relapses, EDSS progression or new combined unique active (CUA) lesions. Due to recruitment delays, the original primary endpoint was changed, allowing study duration and sample size to be reduced. Secondary endpoints at Week 48: mean ARR, % subjects free from any EDSS progression and mean number of new CUA lesions/subject/scan.

Results: 229 patients were randomized to cholecalciferol or placebo. The ITT population (81.2%) had a follow-up of 48 weeks. Demographics and disease activity at baseline were similar between groups. At Week 48 there were no significant differences in DAF status between cholecalciferol and placebo (37.2% versus 35.3%; p=0.912). No significant differences between groups were observed for mean ARR (0.28 versus 0.41; p=0.165) or % subjects free from any EDSS progression (71.7% versus 75.0%; p=0.566). At Week 48, cholecalciferol was associated with a 32% reduction in the number of new CUA lesions versus placebo (p=0.005). The % of subjects free from new T1-hypointense lesions was significantly higher with cholecalciferol versus placebo in patients aged 18–30 years (85.7% versus 46.8%; p=0.006), but not in the ITT population.

Conclusions: Although the primary endpoint was not met, SOLAR did show evidence for the effect of vitamin D₃ supplementation in patients with RRMS, in terms of fewer new CUA lesions. Cholecalciferol supplementation might be more effective in early stages of disease where intense inflammatory activity is likely.

Disclosure: Dr. Hupperts has received personal compensation for activities with Biogen, Merck Serono, Novartis, Sanofi-Aventis as a speaker. Dr. Hupperts has received research support from Biogen and Merck Serono. Dr. Smolders has nothing to disclose. Dr. Vieth has received personal compensation for activities with the Council for Responsible Nutrition, DiaSorin, Merck, and Novartis, Wyeth, and Yoplait as a speaker. Dr. Vieth has received personal compensation for activities with Cytochroma Inc, D Drops Company, DiaSorin and DSM Nutritionals as a scientific consultant. Dr. Vieth has received royalty payments for an infant vitamin D supplement. Dr. Holmøy has received personal compensation for activities with Merck, Biogen Idec, Sanofi and Novartis as a speaker. Dr. Holmøy has received research support from The Research Council of Norway and The Norwegian South-Eastern Health Authorities. Dr. Marhardt has personal compensation for activities with Merck as an employee. Dr. Schluep has received personal compensation for activities with Biogen, Genzyme, Merck, Novartis, Roche and Sanofi-Aventis as a speaker and consultant. Dr. Schluep has received research support from Merck, Novartis and Biogen. Dr. Killestein has received personal compensation for activities with Merck, Biogen, Teva, Genzyme, Roche and Novartis as a speaker and consultant. Dr. Barkhof has received personal compensation for activities with Bayer Schering Pharma, Biogen Idec, Sanofi Genzyme, Janssen Research, Merck Serono, Novartis, Roche, Synthon BV, and Teva Neuroscience as a consultant or a speaker. Dr. Grimaldi has received personal compensation for activities with Bayer HealthCare, Biogen, Merck Serono, Sanofi-Aventis, and Teva as an advisory board member and a speaker. Dr. Grimaldi has received research support from Biogen and the Serono Foundation. Dr. Beelke has received personal compensation for activities with Merck KgaA as an employee.