Checkpoint inhibitors and chronic comedications: A retrospective study on immune-related adverse events

IntroductionImmune checkpoint inhibitors (ICI) are widely used in oncology. By stimulating immunity, their mechanism induces immune-related adverse events (irAE). Some studies suggest that certain drugs may exacerbate these toxicities (dysbiosis). This study aims to assess the link between taking chronic medications and the occurrence of immune-related adverse event during ICI treatment.MethodsThis retrospective monocentric study includes adult patients who started an ICI treatment between 06.01.23 and 12.31.23. Clinical characteristics were extracted from medical records. The use of chronic medicines during ICI treatment was screened. The occurrence of an IRAE within 12 months following ICI initiation was monitored.ResultsA total of 76 patients were included, mainly treated with pembrolizumab (88%). Fifty-four patients (71%) suffered from at least one irAE within one year (41% endocrine, 37% hepatic and 20% dermatological). PPI were the most prescribed chronic drug (33%). Taking chronic treatments was not associated with the occurrence of an IRAE (p = 0.19). Toxicity's severity was not significantly associated with having chronic medication (p = 0.43). No association was found between PPI or NSAID use and digestive toxicity (respectively p = 0.29;p = 0.99). Breast cancer treatment was significantly associated with irAE occurrence (p = 0.02).ConclusionIn this cohort, irAE were highly prevalent. Pembrolizumab-treated patients were predominant and chronic co-medications were not associated with the occurrence of irAE. However, the design of the study, short follow-up and limited sample size may have limited the detection of an effect. In order to anticipate irAE consequences, larger prospective studies are needed to clarify the role of co-medications in their occurrence.