Biotech firms Biogen Idec Inc., of Cambridge, and Genentech Inc., of California, today said that Rituxan failed to meet its goal in a mid- to late-stage study for primary-progressive multiple sclerosis, or PPMS.
During the 96-week trial, 439 patients with the autoimmune disease took either Rituxan or a placebo. Serious adverse events were 16.4 percent with Rituxan, versus 13.6 percent with the placebo.
The companies are continuing to evaluate data from the study and the drug’s long-term safety.
‘‘We are disappointed ... but not surprised, given the significant clinical challenges presented by PPMS,’’ said Hal Barron, Genentech’s chief medical officer.
In multiple sclerosis, the immune system attacks the myelin sheath, inflaming and destroying the fatty, protective substance. Symptoms include weakness and fatigue, numbness, blurred vision, muscle stiffness, and speech problems. PPMS affects about 10 percent of the MS population.
Rituxan is already approved for non-Hodgkin’s lymphoma and rheumatoid arthritis.