2681. Outcomes Related to Respiratory Viral Infections in Cancer Patients on PD-1 Inhibitors

Background The PD-1 inhibitors or check point inhibitors (CPI) are commonly used for the treatment of many solid tumors (ST) and hematological malignancies (HM). By blocking PD-1 in fatigued T cells, an increase in viral clearance may be noted as evidenced in cases of JC virus. Our objective was to assess the outcomes related to cancer patients with microbiologically documented acute respiratory viral infections while on CPI. Methods All patients who were infected with either influenza, respiratory syncytial virus (RSV), parainfluenza virus (PIV), and human metapneumovirus (HMPV) from 9/2016 to 6/2018 with prior or concurrent CPI therapy were included in this study. Demographics and clinical data were collected retrospectively. Comparisons were done between patients with concurrent (group 1) or prior (group 2) CPI therapy. Results A total of 92 cancer patients were identified and of those, 50 patients (54%) were on concurrent CPI therapy at the time of infection. Most patients had ST, mainly non-small cell lung cancer, and most were predominantly infected with Influenza (Figures 1 and 2). Side effects-related to CPI therapy and steroid use prior to infection were uncommon (13%). When compared with group 2, patients in group 1 had a trend toward less lower respiratory tract infections (24% vs. 40%, P = 0.11), decreased median length of stay (3 vs. 8 days, P = 0.1125) and lower 30-day mortality (4% vs. 12%, P = 0.2396). Conclusion Our data demonstrated trends toward improved outcomes in patients with respiratory viral infections on concurrent CPI therapy. Whether improved outcomes are related to enhanced immune responses to these viral infections need to be determined in a larger prospective observational cohort of patients. Disclosures Roy F. Chemaly, MD, MPH, FACP, FIDSA, Chimerix: Advisory Board, Research Grant; Clinigen: Advisory Board; Merck: Advisory Board, Consultant, Grant/Research Support, Research Grant, Speaker’s Bureau; Oxford immunotec: Consultant, Grant/Research Support; Shire: Research Grant, Speaker’s Bureau; Viracor: Grant/Research Support.