Poly adenosine diphosphate ribose polymerase inhibitors maintenance in patients with ovarian cancer: A systematic review and meta-analysis of randomized controlled trials.

e17081 Background: Ovarian cancer is the deadliest of gynecologic cancers and many recur despite achieving a clinical response to initial platinum-based chemotherapy. The use of poly adenosine diphosphate ribose polymerase (PARP) inhibitors maintenance has shown to improve survival in ovarian cancer. Methods: MEDLINE, EMBASE databases and meeting abstracts from inception through January 2019 were queried. Phase 3 randomized controlled trials (RCT) which employed PARP inhibitors maintenance in ovarian cancer were incorporated in the analysis. A generic inverse variance method was used to calculate the estimated pooled hazard ratio (HR) for progression-free survival (PFS) with 95% confidence interval (CI). Heterogeneity was assessed with Cochrane Q -statistic. Random effects were used due to some heterogeneity among studies. Results: Four phase III RCTs with a total of 1792 patients were eligible. The study arm used olaparib or niraparib or rucaparib while the control arm utilized placebo. The randomization ratio was 2:1 in all studies. Participants were sensitive to platinum-based chemotherapy, as newly diagnosed in SOLO-1 trial and had been previously on two such regimens in the other trials, with an objective response. Almost all patients in the SOLO-2 and SOLO-1 trials had a gBRCA mutation, while there were patients with and without the said mutation in the other two studies. The pooled HR for PFS was statistically significant at 0.32 (95% CI: 0.27-0.38; P < 0.0001), including gBRCA cohort (HR, 0.28; 95% CI: 0.24-0.33; P < 0.0001) and non-gBRCA cohort (HR, 0.39; 95% CI: 0.32-0.48; P < 0.0001). Conclusions: Our meta-analysis demonstrated that the use of maintenance therapy with PARP inhibitors significantly improved PFS compared to placebo, regardless of the presence or absence of gBRCA mutation.