PurposeFor patients with severe renal impairment (CrCl ≤ 30 ml/min) or end-stage renal disease (ESRD), olaparib intake is not recommended as the pharmacokinetics and safety of olaparib have not been evaluated in this patient group. Therefore, this valuable patient group is generally excluded from poly(ADP-ribose) polymerase inhibitor (PARPi) therapy. Here we report the pharmacokinetics (PK), efficacy, safety and tolerability of olaparib capsules 200 mg BID in a patient with recurrent epithelial ovarian cancer (EOC) and ESRD requiring hemodialysis.MethodsBlood and dialysate samples of the patient were collected on a dialysis and non-dialysis day. Olaparib total plasma concentrations were determined through high-performance liquid chromatography with tandem mass spectrometric detection. Actual scheduled sample times were used in the PK analysis to determine multiple dose PK parameters at steady state.ResultsMaximum concentration was achieved 1.5 h after drug administration on non- dialysis and after 1 h on dialysis day. The steady-state trough concentration and the maximal plasma concentration were similar on dialysis and non- dialysis day. On non-dialysis day, the AUCss was 30% higher (24.0 µg.h/mL vs. 16.9 µg.h/ml) than on dialysis day. The plasma clearance CLss/F was lower on non-dialysis day. Olaparib was not detectable in the dialysate samples.ConclusionA total dose of olaparib 200 mg BID capsule formulation was well tolerated by our patient with ESRD and hemodialysis. Moreover, this maintenance therapy led to 16 months of progression free survival. Further trials on PARPi therapy in patients with hemodialysis are warranted.