Evaluation of Drug–Drug Interactions Using Drug-PIN® in Patients Receiving Avelumab Maintenance for Advanced Urothelial Carcinoma: Evidence from the MALVA Study (Meet-URO 25)

Introduction: Polypharmacy is common in patients with advanced urothelial carcinoma (UC) receiving avelumab maintenance therapy, raising concerns about potential drug–drug interactions (DDIs). Methods: We retrospectively analyzed patients enrolled in the multicenter MALVA study treated with avelumab maintenance. Concomitant medications were assessed using the Drug Interaction and Pharmacogenomics Information Network (Drug-PIN®). Drug-PIN® scores were calculated with and without avelumab and correlated with overall survival (OS) and progression-free survival (PFS). Results: Among 115 patients, Drug-PIN® scores showed wide inter-patient variability but were not significantly influenced by inclusion of avelumab. No significant differences in OS or PFS were observed across Drug-PIN® risk categories. Conclusion: In this real-world cohort, polypharmacy and Drug-PIN® score did not impact survival outcomes, suggesting that, within the limitations of this exploratory analysis, Drug-PIN®-assessed DDI burden was not associated with survival outcomes in patients receiving avelumab maintenance therapy.