Ofatumumab in Rituximab-Refractory Autoimmune Hemolytic Anemia Associated With Chronic Lymphocytic Leukemia: A Case Report and Review of Literature

Abstract

Clinical Practice Points Chronic lymphocytic leukemia (CLL) is the most prevalent leukemia in the Western world and usually affects individuals older than the age of 65. The main clinical manifestations are lymphocytosis, lymphadenopathy, hepatosplenomegaly, anemia, thrombocytopenia, hypogammaglobinemia, and autoimmune disorders including autoimmune hemolytic anemia (AIHA). Chronic lymphocytic leukemia cells aberrantly coexpress CD5 (a T-cell marker) andCD19 andCD23 (B-cell markers) and they have low-level expression of CD20. Despite advancements in molecular characterization and treatment strategies, CLL remains incurable and most patients do relapse despite chemotherapy. Currently the fludarabine, cyclophosphomide, and rituximab regimen seems to be the best regimen in terms of prolonging survival and maintaining diseasefree progression in untreated and relapsed cases. In relapsed cases, rituximab (a chimeric monoclonal antibody against CD20) monotherapy has been used because of its low adverse effect profile and has been reported to show significantly long response duration in patients after fludarabine induction. Rituximab has been used to treat autoimmune complications of CLL, such as AIHA. Recently, ofatumumab, a fully human monoclonal antibody, that targets a unique epitope on the CD20 molecule that differs from the one targeted by rituximab, has been approved in treatment of fludarabine-refractory CLL. Here we report a case of a 70-year-old woman with the diagnosis of CLL who developed AIHA that was refractory to steroids and rituximab, yet had complete resolution of the hemolysis after ofatumumab treatment. To our knowledge, this is the first case report of ofatumumab for the treatment of AIHA.