Anatomical Therapeutic Chemical Classification System
Ocrelizumab is a recombinant humanised monoclonal antibody that selectively targets CD20-expressing B cells. The precise mechanisms through which ocrelizumab exerts its therapeutic clinical effects in MS is presumed to involve immunomodulation through the reduction in the number and function of CD20-expressing B cells. Following cell surface binding, ocrelizumab selectively depletes CD20-expressing B cells through antibody-dependent cellular phagocytosis (ADCP), antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and apoptosis. The capacity of B-cell reconstitution and preexisting humoral immunity are preserved.