Incorporating Parp-inhibitors in Primary and Recurrent Ovarian Cancer: A Meta-analysis of 12 phase II/III randomized controlled trials

Background: The second decade of 2000s is witnessing a new ovarian cancer (OC) paradigm shift thanks to the results recently obtained by a new class of targeted agents: the Poly(ADP-ribose)polymerase (PARP)-Inhibitors (PARPi). Aim of this meta-analysis is to analyze available results obtained with PARPi, administered alone or in combination with chemo- and/or target-therapies in terms of efficacy and safety for the treatment of recurrent and primary advanced OC. Methods: On December 2019, all published phase II/III randomized clinical studies were systematically searched using the terms "[Parp-Inhibitor] AND [ovar*]". Twelve phase II/III randomized controlled trials were identified, with a total number of 5171 patients included. Results: Results demonstrated that PARPi account for a significant improvement of PFS in both recurrent and primary OC setting, independently from their administration schedule and independently from patients' BRCA mutational status. Moreover, patients harboring a Homologous Recombination Deficiency (HRD) positive testing primary or recurrent OC progress significantly later after PARPi administration/association. Results also reported that PARPi increase the occurrence of severe (G3-G4) anemia. Furthermore, severe fatigue occurred more frequently among patients subjected to PARPi combined with chemotherapy and to PARPi plus Bevacizumab. Finally, a significant increase in severe high blood pressure occurrence was observed when PARPi was added to antiangiogenetics, compared to PARPi alone but a significant decrease in G3-G4 hypertension occurrence was found in PARPi plus bevacizumab users compared to Bevacizumab alone. Conclusions: PARPi are a valid option for the treatment of both primary and relapsed OC patients, with a relative low incidence of severe side effects.