Molecular and clinical predictors of improvement in progression‐free survival with maintenance PARP inhibitor therapy in women with platinum‐sensitive, recurrent ovarian cancer: A meta‐analysis

BACKGROUND The authors performed a meta‐analysis to better quantify the benefit of maintenance poly(ADP‐ribose) polymerase inhibitor (PARPi) therapy to inform practice in platinum‐sensitive, recurrent, high‐grade ovarian cancer for patient subsets with the following characteristics: germline BRCA mutation (gBRCAm), somatic BRCA mutation (sBRCAm), wild‐type BRCA but homologous recombinant‐deficient (HRD), homologous recombinant‐proficient (HRP), and baseline clinical prognostic characteristics. METHODS Randomized trials comparing a PARPi versus placebo as maintenance treatment were identified from electronic databases. Treatment estimates of progression‐free survival were pooled across trials using the inverse variance weighted method. RESULTS Four trials included 972 patients who received a PARPi (olaparib, 31%; niraparib, 35%; or rucaparib, 34%) and 530 patients who received placebo. For patients who had germline BRCA1 mutation (gBRCAm1) (N = 471), the hazard ratio (HR) was 0.29 (95% CI, 0.23‐0.37); for those who had germline BRCA2 mutation (gBRCAm2) (N = 236), the HR was 0.26 (95% CI, 0.17‐0.39); and, for those who had sBRCAm (N = 123), the HR was 0.22 (95% CI, 0.12‐0.41). The treatment effect was similar between the gBRCAm and sBRCAm subsets (P = .48). In patients who had wild‐type BRCA HRD tumors (excluding sBRCAm; N = 309), the HR was 0.41 (95% CI, 0.31‐0.56); and, in those who had wild‐type BRCA HRP tumors (N = 346), the HR was 0.64 (95% CI, 0.49‐0.83). The relative treatment effect was greater for the BRCAm versus HRD (P = .03), BRCAm versus HRP (P < .00001), and HRD versus HRP (P < .00001) subsets. There was no difference in benefit based on age, response after recent chemotherapy, and prior bevacizumab. CONCLUSIONS In platinum‐sensitive, recurrent, high‐grade ovarian cancer, maintenance PARPi improves progression‐free survival for all patient subsets. PARPi therapy has a similar magnitude of benefit for sBRCAm and gBRCAm. Although patients with BRCAm derive the greatest benefit, the absence of a BRCAm or HRD could not be used to exclude patients from maintenance PARPi therapy. BRCA mutation status is able to predict for the magnitude of PARP inhibitor benefit in platinum‐sensitive recurrent high‐grade ovarian tumor. However, the absence of a BRCA mutation or homologous recombinant deficiency in high‐grade ovarian tumor cannot be used to exclude patients from such therapy.