TY - JOUR T1 - Response to single agent PD-1 inhibitor after progression on previous PD-1/PD-L1 inhibitors: a case series JF - Journal for ImmunoTherapy of Cancer JO - J Immunother Cancer DO - 10.1186/s40425-017-0273-y VL - 5 IS - 1 SP - 66 AU - Dylan J. Martini AU - Aly-Khan A. Lalani AU - Dominick Bossé AU - John A. Steinharter AU - Lauren C. Harshman AU - F. Stephen Hodi AU - Patrick A. Ott AU - Toni K. Choueiri Y1 - 2017/12/01 UR - http://jitc.bmj.com/content/5/1/66.abstract N2 - Background Monoclonal antibodies targeting the PD-1/PD-L1 axis have gained increasing attention across many solid tumors and hematologic malignancies due to their efficacy and favorable toxicity profile. With more than 1 agent now FDA-approved in a wide variety of tumor types, and with others in clinical trials, it is becoming more common that patients present to clinic for potential treatment with a second PD-1/PD-L1 inhibitor.Case presentation In this report, we present two patients with renal cell carcinoma and one with melanoma who received PD-1/PD-L1 inhibitors. Upon progression on their first-line PD-1/PD-L1 inhibitors, these patients received a different PD-1 inhibitor (nivolumab in all cases) and all had progressive disease as their best response to the subsequent PD-1 inhibitor. The reported clinical information focuses on the course of the disease and the responses to all treatment regimens.Conclusions Clinicians should refrain from using multiple PD-1/PD-L1 inhibitors sequentially outside of clinical trials until there is sufficient data to support this practice routinely. Prospective studies that allow prior treatment with PD-1/PD-L1 are needed to validate the efficacy and safety of these drugs in the second line or later setting. Furthermore, ongoing efforts that aim to identify mechanisms of resistance to immunotherapy will be informative and may ultimately assist physicians in select the optimal treatment following progression on PD-1/PD-L1 inhibitor.Abbreviations:B2MBeta-2-microglubulin proteinccRCCClear cell renal cell carcinomaECMExtracellular matrixFDAUnited States Food and Drug AdministrationHNSCCHead and neck squamous cell carcinomaIL-2Interleukin-2LAG-3Lymphocyte-activation gene 3NSCLCNon-small cell lung cancerPD-1Programmed cell death protein-1PD-L1Programmed death ligand-1PD-L2Programmed death ligand-2PROCLAIMProleukin® Observational Registry to Evaluate the Treatment Patterns and Clinical Response in MalignancyRCCRenal cell carcinomaTIM-3T-cell immunoglobulin and mucin-domain containing-3VEGFVascular endothelial growth factor ER -