Because of dramatic tumor regressions reported with the anti-programmed death-1 (PD-1) and anti-programmed death ligand-1 (PDL-1) antibodies inhibiting the PD-1 immune checkpoint, non-small cell lung cancer (NSCLC) is now recognized as an immune-modifiable disease. As responses were observed in smaller numbers in phase I trials, the immunologic profiles and unique toxicities of these agents have not been fully established in NSCLC. Moreover, PD-1 checkpoint inhibitors in development by different companies may demonstrate diverse spectrums of activity and toxicity. Although the cytotoxic T-lymphocyte antigen-4 (CTLA-4) checkpoint inhibitors in earlier phase studies appeared to have less impressive responses in NSCLC, their safety profile has been more broadly defined. The anti-CTLA-4 antibody, ipilimumab, has the best characterized immune-related toxicities (predominantly skin, gastrointestinal, hepatic, and endocrine) and management strategies in melanoma. Despite the lack of studies directly comparing these agents, toxicities from PD-1 inhibition seem milder than those of CTLA-4 inhibition, with distinct toxicities of pneumonitis infrequently observed with the BMS-936558 anti-PD-1 antibody, nivolumamb, and frequent mild infusion reactions reported with the BMS-936559 anti-PDL-1 antibody. As lungs are critical organs often already compromised in NSCLC patients, immune-mediated pneumonitis can cause worrisome morbidity and mortality. Even though immune checkpoint inhibitors are being rapidly developed in a multitude of trials, optimal immune-mediated toxicity management has not been determined, is evolving, and will be further explored. Early diagnosis and symptom management with corticosteroids form the basis of treatment. Assessment of new immune-response criteria and use of primary endpoints of overall survival (OS) will be important in the development of these immunotherapies in NSCLC.
Identification of Predictive Biomarkers for Immunotherapy with Immune Checkpoint Inhibitors in Patients with Advanced Non-Small Cell Lung Cancer
