Melanoma Complicating Treatment with Natalizumab for Multiple Sclerosis

To the Editor: We report on two cases of melanoma in women with multiple sclerosis who were treated with natalizumab (Tysabri, Biogen Idec and Elan Pharmaceuticals), a humanized monoclonal antibody against α4 integrins. Patient 1 was a 46-year-old woman who, shortly after receiving her first dose of natalizumab, noticed a rapidly changing mole on her shoulder; on evaluation, it proved to be a thick, nonulcerated melanoma with metastatic disease in the regional lymph nodes. Patient 2 was a 45-year-old woman who had a long-standing ocular nevus that developed into an ocular melanoma after the administration of several doses of . . .