Role of PARP inhibitors beyond BRCA mutation and platinum sensitivity in epithelial ovarian cancer: a meta-analysis of hazard ratios from randomized clinical trials

Roli Purwar, Rakesh Ranjan, Manjusha Pal, Satyanshu K. Upadhyay, Tarun Kumar, Manoj Pandey

PARP inhibitors (PARPi) have a well-established role in platinum-sensitive ovarian cancer (PSOC), in BRCA mutant (BRCAm), and homologous recombination deficiency (HRD) population. However, their role in wild type and homologous recombination proficient population is still not clear. A meta-analysis of hazard ratios (HR) of randomized control trials (RCTs) was conducted to study the role of PARPi. The published RCTs comparing the efficacy of PARP inhibitors alone or in combination with chemotherapy and/or target therapies versus placebo/chemotherapy alone/target therapy alone in primary or recurrent ovarian cancer settings were selected. Progression-free survival (PFS) and overall survival (OS) were the primary endpoints. A total of 14 primary studies and 5 updated studies are considered, consisting of 5363 patients. Overall, HR for PFS was 0.50 [95% CI 0.40-0.62]. HR of PFS was 0.94 [95% CI 0.76-1.15] in the PROC group, 0.41 [95% CI 0.29-0.60] was in HRD with BRCA unknown (BRCAuk), 0.38 [95% CI 0.26-0.57] in HRD with BRCAm, and 0.52 [95% CI 0.38-0.71] in HRD with BRCAwt. In the HRP group, overall HR for PFS was 0.67 [95% CI 0.56-0.80], 0.61 [95% CI 0.38-0.99] in HRD unknown with BRCA wt, and 0.40 [95% CI 0.29-0.55] in BRCAm HR for PFS. Overall, HR for OS was 0.86 [95% CI 0.73-1.031]. The results suggest that PARPi have a meaningful clinical benefit in PSOC, HRD, BRACm, and also in HRP and PROC; however, the evidence is not sufficient to recommend their routine use and further studies are needed to expand their role in the HRP and PROC groups.