Genentech, a member of the Roche Group, has won FDA approval for the first treatment indicated for both relapsing and primary progressive forms of multiple sclerosis (MS).

Ocrevus™ (ocrelizumab) is a humanized monoclonal antibody designed to selectively target CD20-positive B cells, which are thought to be a key contributor to myelin and axonal damage that can lead to disability in people with MS. The drug requires administration by intravenous infusion every 6 months—a first dose of two 300-mg infusions given 2 weeks apart, followed by subsequent doses of single 600-mg infusions.

Based on preclinical studies, Genentech said, Ocrevus is thought to work by binding to CD20 cell-surface proteins expressed on certain B cells, but not on stem cells or plasma cells, thus preserving important functions of the immune system.

Ocrevus will be available in the U.S. within 2 weeks, Genentech said.

“The FDA’s approval of Ocrevus is the beginning of a new era for the MS community and represents a significant scientific advance,” Sandra Horning, M.D., CMO and head of Global Product Development for Roche and Genentech, said in a statement. “We believe Ocrevus, given every 6 months, has the potential to change the disease course for people with MS, and we are committed to helping those who can benefit gain access to our medicine.”

Ocrevus has a reported list price of $65,000—about 25% below that of the Merck KGaA/EMD Serono marketed MS treatment Rebif® (high-dose interferon beta-1a). Genentech said it plans to offer patient assistance programs through Genentech Access Solutions for patients who qualify.

Rebif, indicated for relapsing forms of MS, was approved in Europe in 1998 and in the U.S. in 2002. The drug generated €1.741 billion ($1.873 billion) in product sales last year, down 1.7% from 2015

The FDA based its approval in part on two Phase III studies in which Ocrevus showed superior efficacy compared with Rebif® over a 2-year period on three major markers of disease activity: reducing relapses per year by nearly half, slowing the worsening of disability, and significantly reducing MRI lesions. The OPERA I and OPERA II trials assessed Ocrevus in 1656 participants with relapsing MS—both relapsing-remitting MS and secondary progressive MS with relapses—who were treated for 96 weeks.

FDA approval was also based on a separate Phase III trial, ORATORIO, in which Ocrevus was assessed in 732 participants with primary progressive form of multiple sclerosis (PPMS) who were treated for at least 120 weeks.

ORATORIO results showed Ocrevus was the first and only treatment to significantly slow disability progression and reduce signs of disease activity in the brain (MRI lesions) compared with placebo, with a median follow-up of 3 years, Genentech said.

Results from all three Phase III studies were published in the January 19 issue of the New England Journal of Medicine.

Ocrevus is also the subject of a Marketing Authorization Application that has been validated by the European Medicines Agency and is now under review.