Positive Clinical Trial Results for Ocrelizumab in Primary Progressive Multiple Sclerosis

Effective treatments for primary progressive multiple sclerosis (PPMS) have remained a major unmet need. A phase II study of rituximab in PPMS was overall negative, but subgroup analyses suggested possible benefit in younger and less disabled patients. Similar to rituximab, the investigational drug ocrelizumab depletes B cells via binding by CD20. For this multicenter, randomized, double-blind, placebo-controlled, manufacturer-sponsored phase 3 study, investigators recruited 732 patients with PPMS (age range, 18–55; Expanded Disability Status Scale score 3.0– 6.5 [i.e., mild disability through walker dependent]; disease duration <15 years) who met diagnostic criteria plus the presence of abnormal cerebrospinal fluid. Ocrelizumab or placebo …