MS Speaks

Biogen Reports Top-Line Results from Phase 3 Study Evaluating Natalizumab in Secondary Progressive MS

ASCEND Phase 3 Trial Did Not Meet Primary and Secondary Endpoints; Natalizumab Demonstrated Statistically Significant Effect on Upper Limb Function in Patients


CAMBRIDGE, Mass.--(BUSINESS WIRE)--The Phase 3 ASCEND study investigating natalizumab in the treatment of secondary progressive multiple sclerosis (SPMS) did not achieve its primary and secondary endpoints, Biogen  reported today. 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 enrollment 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.

“While we’re disappointed with these results, we believe this research will provide the MS community important insights into this more advanced patient population, and the benefits that natalizumab may provide in areas such as upper limb function,” said Alfred Sandrock, M.D., Ph.D., group senior vice president and chief medical officer at Biogen. “Given the challenges of treating this advanced stage of MS, these results underscore the importance of treatment early in the course of disease with effective disease-modifying therapies before a patient advances to SPMS.”

SPMS is characterized by ongoing nerve damage or loss and patients experience disability progression with increasingly less frequent relapses. Despite extensive clinical research, treatment options for patients with SPMS are extremely limited and none have demonstrated efficacy in slowing the progression of disability unrelated to relapse.

Natalizumab is a high-efficacy treatment for patients with relapsing forms of MS, including relapsing-remitting MS. The safety and efficacy of natalizumab has been established across a robust clinical program and real-world use with more than a decade of clinical experience demonstrating its benefits on disease progression and sustained efficacy in relapsing MS with a well-characterized safety profile.

Detailed results from ASCEND will be presented at a future medical conference.

About ASCEND

ASCEND (A Study to Characterize the Efficacy of Natalizumab on Disability in SPMS) was a randomized, double-blind, placebo-controlled, Phase 3 trial involving 889 patients in 15 countries. Participants were randomized to receive either natalizumab 300 mg or placebo intravenously every four weeks for 96 weeks.

The primary endpoint of the study was the percentage of patients with confirmed progression of disability on one or more components of ASCEND’s composite endpoint: the Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW) and the 9-Hole Peg Test (9HPT) where progression was confirmed at a second visit at least 6 months later and at week 96.