Premature Ventricular Contractions and Cardiomyopathy while on Ofatumumab for Treatment of Chronic Lymphocytic Leukaemia

Ofatumumab is a monoclonal antibody used in the treatment of recurrent and progressive chronic lymphocytic leukaemia (CLL) and was recently approved for the treatment of multiple sclerosis. We describe the case of a 68-year-old man who presented with complaints of irregular pulse readings while undergoing ofatumumab treatment for recurrent CLL. Electrocardiograms (ECGs) demonstrated premature ventricular contractions (PVCs) which eventually caused cardiomyopathy and failed to resolve despite ablative therapy. Ofatumumab-induced PVCs are confirmed in this case by the existence of documented PVCs on ECGs and the disappearance of these PVCs after the completion of ofatumumab treatment. To the best of our knowledge, there have been no previously reported cases of PVCs associated with ofatumumab in the literature. LEARNING POINTS: Ofatumumab is a potential cause of arrhythmias and should be taken with care, particularly in individuals with underlying cardiac disease. Work-up of arrhythmias should include a comprehensive medication review as they can be caused by medications such as ofatumumab.