Impact of intestinal dysbiosis-related drugs on the efficacy of immune checkpoint inhibitors in clinical practice

Purpose Intestinal dysbiosis has emerged as a biomarker of response to immune checkpoint inhibitors (ICIs). It can be caused by antibiotics, although it may also result from the use of other drugs that have been studied to a lesser extent. The objective of our study was to analyze the association between the use of potentially dysbiosis-related drugs and survival in patients treated with ICIs in the clinical practice. Materials and methods A retrospective, multicenter, cohort study was conducted. Clinicopathological variables were collected and the concomitant use of drugs was analyzed. A descriptive analysis of variables and overall survival, estimated by the Kaplan–Meier method, was performed, and association with various independent variables was assessed using Cox regression. Results We included 253 patients, mainly with non-small cell lung cancer and melanoma. The most commonly used drugs were acid reducers, prescribed to 55.3% of patients, followed by corticosteroids (37.9%), anxiolytic drugs (35.6%), and antibiotics (20.5%). The use of acid reducers (9 vs. 18 months, P