Supplementary Material for: Acute kidney injury in a cancer patient exposed to relugolix and abiraterone

Introduction: Abiraterone acetate is an inhibitor of androgen biosynthesis and is approved as a treatment for metastatic castration-resistant and metastatic castration-sensitive prostate cancer. Neither relugolix nor abiraterone is known to cause acute kidney injury. Case Presentation: A 72-year-old Caucasian man with metastatic prostate cancer presented with non-oliguric severe acute kidney injury (AKI) one week after receiving simultaneous therapy with relugolix and abiraterone. The patient had been on abiraterone for three weeks. His physical examination was unremarkable. Blood work on admission revealed hypocalcemia, and elevated creatinine at 3.6 mg/dL. A kidney biopsy confirmed the diagnosis of a high-grade subacute tubular damage, most likely due to nephrotoxicity. The patient did not respond to intravenous isotonic fluids, the discontinuation of relugolix, abiraterone, and rosuvastatin, as well as to hemodialysis. He died 22 days after hospital admission. Conclusion: We report the first case of biopsy-proven drug-induced AKI in a cancer patient acutely exposed to relugolix and abiraterone. Whether one of these drugs individually, or their combination, was the cause of the AKI is unknown. Nonetheless, our report is hypothesis-generating for further investigations on the effect of these drugs.