Treatment of multiple sclerosis with anti-CD20 antibodies

The recently successful targeting of B cells in patients with multiple sclerosis (MS) using monoclonal antibodies (mAbs) targeting CD20 has established that it is no longer a question of whether B cells contribute, but how they contribute, to MS disease activity. Here, the focus will be to review results that have emerged over the last few years from clinical trials of different anti-CD20 mAbs in patients with MS. We will also consider the biological basis underlying the apparent therapeutic efficacy of B cell depletion in MS. To this end, we will draw on several instructive observations made in MS patients who were treated with the anti-CD20 mAb rituximab. While the initial application of rituximab to patients with MS was based on the concept that B cell depletion may translate into decreases in potentially pathogenic CNS-autoreactive antibodies, insights from these studies have underscored the importance of non-antibody mediated functions of B cells.