Complete Response to Anti-PD-1 Antibody Monotherapy in Metastatic Melanoma-Can Therapy be Discontinued? A Review of Current Literature

Newer immunotherapeutic agents such as Nivolumab and Pembrolizumab have changed the landscape of management of metastatic melanoma, with a subset of patients achieving durable responses. The ideal duration of therapy in patients who achieve a complete response with these agents has not been determined. We report a case of a 68 year old man with metastatic melanoma who progressed with Ipilimumab and BRAF-directed therapies, but achieved a complete response with Nivolumab monotherapy and continues to be in remission at almost 2 years after discontinuation of treatment. Review of the current data indicates that discontinuation of anti-PD-1 antibodies after complete response is achieved is feasible. The majority of these patients maintain their responses long-term. In those who relapse, re-treatment with the same agent is effective in most cases according to the current data. Prospective studies are necessary to determine the optimal duration of therapy and strategies to maximize the benefit of these drugs.