Ocrelizumab‐induced colitis: VigiBase disproportionality analysis, case reports and literature review

Aims Ocrelizumab is a humanized anti‐CD20 monoclonal antibody used in multiple sclerosis. Since its commercialization, several cases of ocrelizumab‐induced colitis have been reported in the scientific literature. Methods To explore the potential association of ocrelizumab with colitis as an adverse drug reaction (ADR), we conducted a descriptive and disproportionality analysis of ocrelizumab‐induced colitis registered in VigiBase, as well as an extensive literature review and a description of two cases from Luxembourg reported to our pharmacovigilance centre. Results Our VigiBase analysis revealed 400 cases of ocrelizumab‐induced colitis, with 79.0% serious cases and a median time to onset of 17 months. The preferred term (PT) coded was ‘colitis’ (53.0%), followed by PTs related to inflammatory bowel diseases (33.5%). Significant disproportionality was found for high‐level term ‘colitis’ and for ‘colitis’, ‘colitis microscopic’ and ‘immune‐mediated enterocolitis’ PTs. Our literature review revealed 24 case reports corresponding to 36 patients with a median time to onset of 18 months and a predominance of unspecified colitis (61.1%) and inflammatory bowel diseases (27.8%). Two patients relapsed after ocrelizumab resumption. Conclusions Together, our findings of two relevant clinical cases of ocrelizumab‐induced colitis, the literature review and the significant VigiBase disproportionality, suggest a potential safety signal for ocrelizumab.