Biogen Idec announced that the experimental oral therapy BG-12 significantly reduced the average number of annual MS relapses in a two-year, Phase III clinical trial of more than 1400 people with relapsing-remitting MS. Although its exact mode of action is not known, BG-12 is thought to inhibit immune cells and molecules involved in MS attacks on the brain and spinal cord. The results of the CONFIRM study were announced in an October 26 press release. Data analysis is ongoing and the company expects to provide a full report at an upcoming medical meeting. Positive results from another Phase 3 trial of BG-12 were also announced this year, paving the way for a potential application for marketing approval.
Background: Multiple sclerosis involves immune system attacks against brain and spinal cord tissues. Although its exact mechanism of action is not known, BG-12, an oral drug, is thought to inhibit immune cells and molecules and may be protective against damage to the brain and spinal cord. In an earlier phase II study, compared to inactive placebo, the highest tested BG-12 dose led to a 69% reduction in gadolinium-enhanced (a contrast agent) disease activity on MRI scans from weeks 12 to 24. Earlier in 2011, Biogen Idec announced positive results in another phase III study, the DEFINE trial (read more). Further details on these results were presented at the joint meeting of the European and Americas Committee for Treatment and Research in MS (ECTRIMS/ACTRIMS) last week.
This Study: The primary goal of the CONFIRM study was to determine whether BG-12 could reduce the average annual MS relapse rate at two years. Secondary objectives included assessing BG-12’s effects on the proportion of people who had relapses, disability progression, and disease activity detected by MRI. Safety and tolerability were also assessed.
Participants were randomly assigned to one of two treatment groups receiving different oral doses (240 mg twice each day and 240 mg three times each day), a group receiving glatiramer acetate (Copaxone®, Teva Pharmaceutical Industries, an approved, injected therapy for MS) or a group receiving placebo. Both BG-12 groups and Copaxone were compared to the placebo groups, but not to each other.
According to the press release, in both groups taking BG-12, the primary endpoint was met; the average number of MS relapses in a year was reduced by 44% versus placebo in the lower-dose group, 51% in the higher-dose group, and 29% in the Copaxone group. Disease activity on MRI and the proportion of patients experiencing relapses also were reduced significantly more in the BG-12 groups versus placebo. Disability progression was not reduced significantly more in the BG-12 groups than in the placebo group. According to the press release, the most common adverse events in the BG-12 groups were flushing and gastrointestinal events.
Comment: Full details and evaluation of this study should help to define further the safety and promise of BG-12 as a potential therapy for relapsing MS. According to the company press release, these positive results set the stage for upcoming filings for marketing approval from drug regulatory agencies.