Investigating the influence of baseline medications on immune checkpoint inhibitor treatment outcomes for cancer patients 3706

Abstract Description Immune checkpoint inhibitors (ICIs) are first-line treatment options for many cancer patients. However, ICI treatment resistance and risk of immune-mediated toxicities continue to impact therapeutic success. Concomitant medications are increasingly recognized for their immunomodulatory properties, yet interactions within complex cancer regimens are underexplored. Leveraging data from PICI’s RADIOHEAD cohort, a prospective collection of over 1000 cancer patients receiving first-line ICI treatment in a real-world setting aligned with longitudinal samples, we characterized associations between baseline medication use and ICI outcomes. Utilizing univariate and multivariate cox regression analyses, patients exposed to baseline opioids, systemic corticosteroids, anti-emetics, laxatives, beta-blockers, and benzodiazepines had significantly worse overall survival (OS) compared to patients without these medications, while thyroid medication exposure correlated with significantly improved OS. Visualization of co-prescription patterns indicated overlap between patients receiving opioids, laxatives, and anti-emetics, but not with corticosteroids, beta-blockers, and benzodiazepines. Baseline opioid use was also linked to irAE occurrence. To our knowledge, this is the first study leveraging dimensionality reduction to explore interactions across multiple medication classes in cancer patients. We will next interrogate whether these medication exposures change peripheral immune dynamics. Funding Sources NA Topic Categories Tumor Immunology: Checkpoints, Prevention, and Treatment (TIPT)