A Cochrane review included 6 RCTs with a total of 1589 MS patients. Patients had either relapsing-remitting MS (RRMS, 4 studies) or chronic MS (CMS, 2 studies). Glatiramer acetate (GA) or matching placebo was administered either by subcutaneous injections once or twice daily or, in one trial, orally as 5 or 50 mg tablets. The treatment times varied between 9 and 36 months. In RRMS, a slight decrease in the mean Expanded Disability Status Scale (EDSS) score (WMD= -0.33, 95% CI -0.58 to -0.08 and WMD= -0.45, 95% CI -0.77 to -0.13) was found, respectively, at 2 years and 35 months. The risk of progression was not significantly modified by the therapy at 2 years: RR 0.75 (95% CI 0.51 to 1.12) and at 35 months: RR 0.81 (95% CI 0.50 to 1.29) (2 studies, n=226). No benefit was shown in CMS patients: mean EDSS scores increased from baseline by 0.58+/-1.00 point in the GA group and 0.61+/-1.13 in the placebo group (1 study, n=943). Risk of progression was not reduced, either, for CMS patients: at 1 year RR 0.88 (95% CI 0.60 to 1.27), at 2 years RR 0.84 (95% CI 0.60 to 1.19) and at 3 years RR 0.75 (95% CI 0.38 to 1.50). IN RRMS relative risks of experiencing no relapses were, respectively: 1.28 (95% CI 1.02 to 1.62) within 1 year of treatment, 1.39 (95% C I 0.99 to 1.94) at 2 years and 1.33 (95% CI 0.86 to 2.06) at 35 months (3 trials, n=255). Magnetic imaging parameters, being surrogates of therapeutic efficacy, were not evaluated here. No major toxicity was associated with GA. The most common systemic adverse event was a transient and self-limiting reaction of flushing, chest tightness, sweating, palpitations and anxiety (RR 3.27, 95% CI 2.07 to 5.16). Local injection-site reactions were observed in up to a half of patients treated with GA, thus making a blind assessment of outcomes questionable.
Comment: The quality of evidence is downgraded by limitations in study quality (lack of blinding, short follow-up) and by imprecise results (limited study size for each comparison)