Neurologist and leading MS researcher Dr. Amit Bar-Or from the Montreal Neurological Institute at McGill University presented data on an emerging MS treatment called ofatumumab at the American Academy of Neurology Annual Meeting last week. Ofatumumab is a monoclonal antibody targeted against a protein commonly found on B cells called CD20. It is currently indicated for the treatment of chronic lymphocytic leukemia, but has been recently identified as a potential treatment of autoimmune diseases such as MS.
Dr. Bar-Or presented results from a phase II clinical trial looking at the safety, efficacy and dose response of ofatumumab in people with relapsing-remitting MS.
The study recruited 231 participants who were randomly assigned to one of 5 treatment groups: 3mg every 3 months, 30mg every 3 months, 60mg every 3 months, 60mg every month, and placebo (mock treatment). Participants were given ofatumumab via under-the-skin injections over a period of 6 months and also took part in follow-up studies. The efficacy – ability to produce a beneficial effect – of ofatumumab was determined by its ability to reduce lesions as observed on MRI.
At 12 weeks, treatment with ofatumumab resulted in a significant reduction in the number lesions compared to placebo. The reduction in lesions was observed for all doses. Researchers also reported a linear relationship between suppression of B cell activity and residual disease activity, with 1 new lesion per year with treatment versus 16 new lesions per year without treatment. The drug showed a good safety profile, with reports of some adverse events including injection-site reactions. There were no serious infections, PML cases or immunogenicity (immune reactions against the drug) observed.
Ofatumumab, which is currently being developed by pharmaceutical company GlaxoSmithKline, adds to the growing list of MS therapies in the pipeline. It is also one of two emerging MS therapies targeting B cells, the other being ocrelizumab. Like ofatumumab, ocrelizumab targets the CD20 protein and is currently in phase III trials led by scientists at Roche.
B cells have gained increasing interest among the MS research community over the years. When trials involving B-cell targeted treatments showed marked improvements in people with MS, researchers acknowledged that B cells are important players in MS disease. Last year, the MS Society and MS Scientific Research Foundation launched a $3.6 million dollar collaborative, multi-site study led by Dr. Bar-Or which seeks to understand how different types of B-cells impact the development and progression of MS, how they may have a role in progressive MS, and how they can be therapeutically targeted to improve health without harming other parts of the immune system. I had a chance to chat with Dr. Bar-Or after his presentation at the conference to get a more in-depth look at ofatumumab and B cells.
Here is what he shared with me.