Obinutuzumab Plus Chlorambucil in a Patient with Severe Myasthenia Gravis and Chronic Lymphocytic Leukemia

Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction, characterized by fatigable weakness of the extraocular, bulbar, and limb musculature; prevalence is estimated at 14 to 32 per 100,000 in North America. Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults, resulting from clonal expansion of B-cells in blood, marrow, and secondary lymphoid tissues. The simultaneous presentation of MG and CLL is exceedingly rare. This article presents the case of 71-year-old man diagnosed simultaneously with MG and CLL. His MG was severe and refractory to treatment; therefore, a strategy of treating his coexisting CLL with obinutuzumab and chlorambucil was pursued. Following 6 cycles of obinutuzumab and chlorambucil, his CLL is in remission and his MG is almost entirely undetectable. This is the first case report describing the use of obinutuzumab, a novel anti-CD20 monoclonal antibody, in a patient with concurrent MG and CLL.