Weighing the role of concomitant medications during PD-1/PD-L1 checkpoint blockade: A preliminary analysis.

e15132 Background: The role of concomitant medications, such as steroids, antibiotics and proton pump inhibitors, during immunotherapy has already been investigated, without conclusive results. Methods: This is a multicenter retrospective study, of advanced cancer patients (any histology) treated with anti-PD-1/PD-L1 immunotherapy. Baseline concomitant medications were collected. Results: From June 2014 to November 2019, 277 consecutive patients were evaluated. Median age was 69 years; male/female ratio was 190/87. Primary tumors were: NSCLC (41.9%), melanoma (40.1%), renal cell carcinoma (11.9%) and others (6.1%). 63 patients (22.7%) had ECOG-PS ≥ 2. 120 patients (43.3%) had ≥ 2 metastatic sites. Conclusions: Cancer-related steroids administration, systemic antibiotics, proton pump inhibitors, anticoagulants, opioids, oral anti-diabetics and insulin therapy seem to significantly affect survival in patients receiving PD-1/PD-L1 inhibitors. In interpreting such data, it is important to consider the prevalent role of poor clinical condition. Our preliminary results warrant further investigation in a larger cohort of patients and in a perspective way. [Table: see text]