Safety and Immunogenicity of mRNA Vaccines Against Severe Acute Respiratory Syndrome Coronavirus 2 in Patients With Lung Cancer Receiving Immune Checkpoint Inhibitors: A Multicenter Observational Study in Japan

INTRODUCTION: Patients with cancer have been prioritized for vaccination against severe acute respiratory syndrome coronavirus 2. Nevertheless, there are limited data regarding the safety, efficacy, and risk of developing immune-related adverse events (irAEs) associated with mRNA vaccines in patients with lung cancer, especially those being actively treated with immune checkpoint inhibitors. METHODS: This multicenter observational study was conducted at nine hospitals in Japan. Patients with lung cancer (≥20 y) actively treated with immune checkpoint inhibitors between 4 weeks prefirst vaccination and 4 weeks postsecond vaccination were enrolled. The primary end point was the incidence of irAEs of any grade on the basis of an assumed incidence without vaccination rate of 35%. Immunogenicity was assessed by measuring anti–spike (S)-IgG antibody levels against severe acute respiratory syndrome coronavirus 2. RESULTS: A total of 126 patients with lung cancer (median age, 71 y; interquartile range, 65–74) were enrolled from May to November 2021 and followed up until December 2021. There were 26 patients (20.6%, 95% confidence interval: 13.9%–28.8%) and seven patients (5.6%, 95% confidence interval: 2.3%–11.1%) who developed irAEs of any grade pre- and postvaccination, respectively, which was lower than the predicted incidence without vaccination. None of the patients experienced exacerbation of preexisting irAE postvaccination. S-IgG antibodies were seroconverted in 96.7% and 100% of the patients with lung cancer and controls, respectively, but antibody levels were significantly lower in patients with lung cancer (p < 0.001). CONCLUSIONS: Patients with lung cancer who were actively treated with ICIs were safely vaccinated without an increased incidence of irAEs; however, their vaccine immunogenicity was lower. This requires further evaluation.