Twice Weekly Versus Daily Glatiramer Acetate: Results of a Randomized, Rater-Blinded Prospective Clinical Trial Clinical and MRI Study in Relapsing-Remitting MS

OBJECTIVE: To investigate in a small pilot study the safety, tolerability, and efficacy of glatiramer acetate (GA) 20 mg injected subcutaneously (SC) twice a week versus GA administered 20 mg SC daily in RRMS. BACKGROUND: The optimal dose of GA in RRMS remains unknown. We have previously shown that GA administered on alternate days appears to be as effective as daily GA. There is considerable interest in identifying the optimal dose of GA in RRMS. DESIGN/METHODS: We conducted a prospective, randomized, rater-blinded 2 year study to compare GA 20 mg SC twice a week to GA 20 mg SC daily. RRMS patients receiving GA 20 mg SC daily for at least one year were randomized to either continue in the same fashion or switch to GA 20 mg SC twice weekly. EDSS were recorded every 6 months and to confirm relapses, while brain MRI scans were done at baseline and month 24. RESULTS: 48 RRMS were randomized into equal groups of GA 20 mg SC daily or GA 20 mg SC twice-weekly. Both groups were well-matched. After two years, the annualized relapse rate, mean EDSS, proportion of relapse-free patients, and the proportion of patients without disease progression were similar in the two groups. Brain MRI also did not demonstrate any significant changes in T2W or T1W lesion, or in the percentage brain volume change. However, the incidence of lipoatrophy, local injection site reactions, and immediate-post injection systemic reactions were significantly lower in the GA twice-weekly group. CONCLUSIONS/RELEVANCE: This study provides further evidence that GA administered less frequently than daily may be as efficacious and better tolerated than GA administered daily. This may have a significant impact in the clinical use of GA. Larger, multi-center studies are warranted to confirm our findings and investigate the optimal dose of GA in RRMS. Supported by: Wayne State University Neuroscience Program.