Tysabri does not achieve endpoints in secondary progressive MS in ASCEND study- Biogen

The Phase III ASCEND study investigating Tysabri (natalizumab) from Biogen in the treatment of secondary progressive multiple sclerosis (SPMS) did not achieve its primary and secondary endpoints, Biogen reported. During the study, natalizumab was generally well tolerated and adverse events were consistent with its known safety profile.

ASCEND evaluated the efficacy and safety of natalizumab to slow the accumulation of disability progression unrelated to relapse in SPMS patients, an unmet medical need. The majority of study participants had EDSS scores of 6.0 to 6.5 (walking aid required) and were non-relapsing for two years prior to enrolment in the study. The study’s composite primary endpoint evaluated the percentage of patients whose disability had progressed on one or more of three disability measurements comprising the composite endpoint. Natalizumab demonstrated a statistically significant effect on upper limb function (one of the three components of the primary composite endpoint) unrelated to relapses. Consistent with the established effects of natalizumab in relapsing multiple sclerosis, analyses of exploratory endpoints suggest that some patients received a benefit from treatment, including reduction of relapses and new MRI lesions.

Comment: The drug did not show a decrease in the progression of disability unrelated to relapses but some positive effect on upper limb function. SPMS is a form of MS that follows after relapsing remitting MS. Biogen had studied Tecfidera (dimethyl fumarate) in this condition but now has stopped development of both Tysabri and Tecfidera in SPMS.