Antibiotic Use Does Not Appear to Influence Response to Nivolumab

Microbiota is known to influence response to anticancer immunotherapy. We examined whether antibiotic usage could impact nivolumab efficacy in patients treated for non-small-cell lung cancer (NSCLC). Seventy-four patients with NSCLC were included in this retrospective study. They received nivolumab between 2015 and 2016 (3 mg/kg i.v. q2w). The association between RECIST response and antibiotic usage was determined using Chi-square and Cox proportional hazard model. A total of 17, 21 and 36 patients experienced response, stable disease and progression disease under nivolumab. Only 15 (20.3%) patients were exposed to antibiotic medication in the 3 months before the first nivolumab injection or during treatment. We found a similar response rate for the two populations, without impact of antibiotic exposure (Chi-square test p=0.75). Moreover, we observed no impact of antibiotic medication on progression-free survival under nivolumab (log-rank test, p=0.72). Microbiota modification induced by antibiotics does not appear to affect the efficacy of nivolumab in patients with NSCLC.