The US Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation for the investigational medicine ocrelizumab (OCREVUS™) for the treatment of people with primary progressive multiple sclerosis (PPMS). There is currently no approved treatment for PPMS - a debilitating form of MS characterized by progressive, worsening symptoms and typically without distinct relapses or periods of remission.
Ocrelizumab is an investigational, humanized monoclonal antibody designed to selectively target CD20-positive B cells, a specific type of immune cell. These immune cells are thought to be a key contributor to myelin (nerve cell insulation and support) and axonal (nerve cell) damage, which can result in 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, and therefore important functions of the immune system may be preserved.
Breakthrough Therapy Designation is designed to expedite the development and review of medicines intended to treat serious or life-threatening diseases. In this case, the designation is based on positive results from the pivotal Phase III study (called ORATORIO), which showed treatment with ocrelizumab significantly reduced disability progression and other markers of disease activity compared with a placebo.
Ocrelizumab reduced the risk for progression of clinical disability sustained for at least 12 weeks by 24 percent compared with a placebo. Additionally, ocrelizumab was superior to a placebo in significantly reducing the risk for progression of clinical disability for at least 24 weeks by 25 percent and the time required to walk 25 feet by 29 percent.
Ocrelizumab is the first investigational medicine to show positive study results in both primary progressive and relapsing forms of multiple sclerosis. Three pivotal Phase III studies will be submitted to global regulatory authorities in the first half of 2016.
OCREVUS is the proprietary name submitted to global regulatory authorities for the investigational medicine ocrelizumab.