Effectiveness
A 2004 Cochrane review concluded that Glatiramer acetate "did not show any beneficial effect on the main outcome measures in MS, i.e. disease progression, and it does not substantially affect the risk of clinical relapses."
In its pivotal trial of 251 patients, after two years Copaxone failed to show any advantage in halting disability progression.
As a result, Copaxane is approved by the FDA for reducing the frequency of relapses, but not for reducing the progression of disability.
A 15-year followup of the original trial compared patients who continued with glatiramer to patients who dropped out of the trial. Patients with glatiramer had reduced relapse rates, and decreased disability progression and transition to secondary progressive MS, compared to patients who did not continue glatiramer. However, the two groups were not necessarily comparable, as it was no longer a randomized trial. There were no long-term safety issues.
In two recent studies, both reported at the 2007 ECTRIMS meeting, the efficacy of glatiramer acetate was compared to high-dose/high-frequency interferon beta. In the REGARD study, Rebif was compared to glatiramer, and in the BEYOND study, Betaseron was compared to glatiramer. In both trials, there was no significant difference between interferon and glatiramer in the primary endpoints (time to relapse) or in any clinical endpoints, although some differences in MRI measures of disease activity have been claimed.
A double-blind 3-year study found no effect of glatiramer acetate on Primary-Progressive Multiple Sclerosis.
Copaxone has FDA approval for clinically isolated syndrome, based on the PreCISe trial, which showed that glatiramer delayed the progression from the first clinical event to clinically definite multiple sclerosis with a risk reduction of 45%. 43% of patients in the placebo group converted, compared to 25% in the glatiramer group.
Read more about this topic: Glatiramer Acetate