Glatiramer acetate 20mg subcutaneous twice-weekly versus daily injections: results of a pilot, prospective, randomised, and rater-blinded clinical and MRI 2-year study in relapsing-remitting multiple sclerosis

OBJECTIVE: The optimal dose of glatiramer acetate (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 studying a more patient friendly dosing regimen of GA that may be as efficacious and better tolerated than daily GA. METHODS: We conducted a prospective, randomized, rater-blinded study to compare the clinical and MRI outcomes of GA 20 mg SC administered twice a week to GA administered 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. Clinical assessments including EDSS were performed every 6 months and brain MRI scans were obtained at baseline and month 24. RESULTS: 48 RRMS were randomized into two equal groups of either GA 20 mg SC daily or GA 20 mg SCbi-weekly. Both groups were well matched for clinical demographics and MRI features at baseline. All patients remained in the study for the entire duration. 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 differences in T2W or T1W lesion, or in the percentage brain volume change between the two groups. However, the incidence of lipoatrophy, local injection site reactions, and immediate post injection systemic reactions were significantly lower in the GA twice-weekly group. Detailed analysis of the results will be presented. CONCLUSION: 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 on improving compliance and tolerability while maintaining the desired immunomodulating effect of GA. Furthermore, this may also have a favorable economic impact. Larger, multi-center studies are warranted to confirm our findings and address a critical need of the MS patient community.