Background and Importance Poly (ADP-ribose) polymerase (iPARP) enzyme inhibitors, have recently revolutionised high-grade epithelial ovarian cáncer treatment. These new drugs have a new efficacy and safety profile. Currently, there are three iPARP approved: olaparib, niraparib and rucaparib.

Aim and Objectives Review effectiveness and safety of olaparib and niraparib (iPARP), according to standard clinical practice, in patients with high-grade epithelial ovarian cancer.

Material and Methods Retrospective observational study, in a tertiary care hospital, included patients with high-grade epithelial ovarian cancer who started treatment with olaparib or niraparib between May 2019 and December 2020. We collected demographic, patient clinical data, tumour-specific and treatment variables. Data were extracted from electronic medical records. Efficacy variables used: overall survival (OS) and progression-free survival (PFS). Survival analysis was performed using the Kaplan-Meier method. Safety variables used were adverse events (AEs), temporary discontinuations, dose reductions and/or discontinuations due to toxicity.

Results Thirty-four patients were included, 44.1% on olaparib and 55.9% on niraparib. The median age was 59 years (IQR 53 – 68). All of them present a baseline ECOG between 0 and 1. All patients who received olaparib had mutated BRCA, while those who received niraparib had BRCA wildtype. Median follow-up was 15.6 (IQR 9.8–29.5) months.

Eighty-five point three per cent of our patients received maintenance treatment with an iPARP after relapse. Median PFS and OS were not reached in the olaparib group. Median PFS with niraparib was 11.30 (95% CI = 2.65–19.95) months and median OS was 36.01 (95% CI = 13.37–58.64) months.

On olaparib group, 93.3% of patients experienced an AE. Of these, 20% required temporary discontinuation and 20% required dose reduction due to toxicity. All niraparib-treated patients reported AEs, 57.9% required temporary discontinuation and 52.6% required dose reduction. Grade ≥3 AEs occurred in 33.3% patients on olaparib group and 63.1% with niraparib. No patient discontinued treatment due to toxicity.

Conclusion and Relevance Olaparib and niraparib achieve relevant results in patient survival. The differences respect to pivotal trials could be explained by a greater knowledge on the use of these drugs, which allows a better selection of the patients to be treated. In terms of safety, most patients experience some AEs during treatment, which are reversible and controllable with dose reduction.

Conflict of Interest No conflict of interest