Checkpoint Blockade in Melanoma Patients With Underlying Chronic Lymphocytic Leukemia.

Chronic lymphocytic leukemia (CLL) is associated with immune dysfunction and an increased risk of melanoma. For patients with metastatic melanoma, immunotherapy with checkpoint blocking antibodies is a standard of care. In patients with concomitant CLL and metastatic melanoma, it is not known whether CLL might influence the antimelanoma efficacy or immune-related toxicities of immune checkpoint blockade. Fifteen patients with locally advanced or metastatic melanoma and a concomitant diagnosis of CLL who received pembrolizumab or ipilimumab with or without nivolumab for the treatment of their melanoma at Memorial Sloan Kettering Cancer Center between January 1, 2010, and January 1, 2017, were retrospectively identified. Clinical characteristics including absolute lymphocyte counts during therapy were recorded along with a response to treatment (objective radiographic response, progression-free survival, and adverse events) for each patient. Of 9 response-evaluable patients treated with ipilimumab, 3 (33%) had a partial response, 1 (11%) had stable disease, and 5 (56%) developed progressive disease. Objective tumor responses were also observed with single-agent therapy pembrolizumab and with combination therapy of nivolumab and ipilimumab. Grade 3 or 4 toxicity was observed in 6 of 15 patients (40%), including diarrhea, transaminitis, rash, and hemolytic anemia. Although our retrospective assessment was limited, there was no evidence that CLL responded to the checkpoint blockade. This case series demonstrates that ipilimumab, pembrolizumab, and combined ipilimumab and nivolumab therapies show clinical activity in patients with melanoma and concomitant CLL, at rates consistent with those previously reported. This population may warrant closer surveillance for hematologic immune-related toxicities such as autoimmune hemolytic anemia.