Three times weekly glatiramer acetate in relapsing-remitting multiple sclerosis.

OBJECTIVE To assess the efficacy and safety of glatiramer acetate (GA) 40mg administered 3× weekly (tiw) compared with placebo in patients with relapsing-remitting multiple sclerosis (RRMS). METHODS This randomized, double-blind study was conducted in 142 sites in 17 countries. Patients with RRMS with at least 1 documented relapse in the 12 months before screening, or at least 2 documented relapses in the 24 months before screening, and an Expanded Disability Status Scale score ≤ 5.5, were randomized 2:1 to receive either subcutaneous (sc) GA 40mg tiw (1ml) or placebo for 12 months. RESULTS Of 1,524 patients screened, 1,404 were randomized to receive GA 40mg sc tiw (n = 943) or placebo (n = 461). Ninety-three percent and 91% of patients in the placebo and GA groups, respectively, completed the 12-month study. GA 40mg tiw was associated with a 34.0% reduction in risk of confirmed relapses compared with placebo (mean annualized relapse rate = 0.331 vs 0.505; p < 0.0001). Patients who received GA 40mg tiw experienced highly significant reduction (p < 0.0001) in the cumulative number of gadolinium-enhancing T1 (44.8%) and new or newly enlarging T2 lesions (34.7%) at months 6 and 12. GA 40mg tiw was safe and well tolerated. The most common adverse events in the GA group were injection site reactions (35.5% with GA vs 5.0% with placebo). INTERPRETATION GA 40mg sc tiw is a safe and effective regimen for the treatment of RRMS, providing the convenience of fewer sc injections per week.