The FDA has accepted for review a biologics license application for ocrelizumab (Ocrevus, Genentech) for the treatment of patients with relapsing multiple sclerosis (RMS) or primary progressive multiple sclerosis (PPMS). The agency has granted the application a priority review designation, with a targeted action date of December 28, 2016. If approved, ocrelizumab would be the first treatment indicated for both forms of MS, which affect approximately 95% of MS patients at diagnosis.
A priority review designation is granted to medications that have the potential to provide significant improvements in the treatment of a serious disease. In February 2016, the FDA granted breakthrough therapy status to ocrelizumab for the treatment of PPMS. Ocrelizumab is the first investigational medication to receive a breakthrough therapy designation in MS.
Ocrelizumab is an investigational, humanized monoclonal antibody designed to selectively target CD20-positive B cells, a specific type of immune cell thought to be a key contributor to myelin (nerve cell insulation and support) and axonal (nerve cell) damage. This nerve cell damage can lead to disability in people with MS. Based on preclinical studies, ocrelizumab binds to CD20 cell surface proteins expressed on certain B cells, but not on stem cells or plasma cells.
The ocrelizumab marketing application was based on positive results from three phase 3 studies that met their primary and key secondary endpoints. OPERA I and OPERA II were identical, randomized, double-blind, double-dummy, global studies that evaluated the efficacy and safety of ocrelizumab (600 mg administered by intravenous infusion every six months) compared with interferon beta-1a (44 mcg administered by subcutaneous injection three times per week) in 1,656 subjects with RMS (i.e., relapsing-remitting MS and secondary-progressive MS with relapses). ORATORIO was a randomized, double-blind, global study that evaluated the efficacy and safety of ocrelizumab (600 mg administered by intravenous infusion every six months) compared with placebo in 732 subjects with PPMS.
Data from the OPERA I and OPERA II trials in patients with RMS demonstrated the superior efficacy of ocrelizumab in reducing annualized relapse rates and disability progression compared with interferon beta-1a (Rebif, EMD Serono). Data from the ORATORIO trial in patients with PPMS showed significant reductions in disability progression as well as in as other measures of progressive disease compared with placebo. Overall safety (i.e., the proportion of patients with adverse events and serious adverse events) of ocrelizumab in the phase 3 studies was similar to interferon beta-1a in the RMS studies and to placebo in the PPMS study. The most common adverse events associated with ocrelizumab were infusion-related reactions and infections, which were mostly mild-to-moderate in severity.
RMS is the most common form of MS. Disease activity and progression can occur even when people do not show signs or symptoms of MS, despite available relapsing MS treatments. PPMS is a debilitating form of MS marked by steadily worsening symptoms but typically without distinct relapses or periods of remission. Approximately one in 10 people with MS are diagnosed with the primary progressive form of the disease. There are no approved treatments for PPMS.
Source: Genentech; June 27, 2016.