[B-cell depletion in the therapy of multiple sclerosis: ofatumumab is a new player]

Research results in recent years have demonstrated that B-lymphocytes play a crucial role in the pathogenesis of multiple sclerosis (MS). The increased understanding of the disease process has resulted in the development of B cell-targeting antibodies as potential drugs for both relapsing and progressive forms of MS. Therefore, B-cell depletion therapies are becoming more prominent and determining in reducing disease progression. The first B-cell depleting anti-CD20 monoclonal antibody was rituximab, which has also been studied in MS and, following favourable results, new drugs have been developed with a similar point of attack. In 2017, the FDA and in 2018, the EMA approved ocrelizumab, another anti-CD20 monoclonal antibody, for the treatment of relapsing-remitting (RRMS) and primary progressive multiple sclerosis (PPMS). This was a particularly significant advance in the treatment of PPMS, as it was the first medication with a proven effect of reducing progression in PPMS. Ofatumumab, a fully human anti-CD20 monoclonal antibody, has emerged recently as a new player in B-cell depletion therapy. The drug has also recently been approved by the EMA in March 2021 for use in relapsing forms of MS. In this review, we detail the mechanism of action and efficacy of anti-CD20 therapies currently used in MS.