No abstract

TPS5598 Background: Ovarian cancer (OC) is the leading cause of death from gynecologic cancers in US women. Despite high response rates to first-line treatment, ~70% of patients (pts) relapse within 3 years and then remain largely incurable. First-line treatment needs to be improved to achieve long-term remission in pts and improve the cure rate. The Phase III SOLO1 trial showed a meaningful clinical benefit for olap maintenance therapy in newly diagnosed OC pts with a BRCA mutation (Moore et al N Engl J Med 2018). Preliminary data suggest that combining a PD-L1 inhibitor, anti-angiogenic and PARP inhibitor (triplet therapy) may achieve a synergistic antitumor effect. The DUO-O study (NCT03737643) evaluates the efficacy and safety of treatment combinations involving standard-of-care platinum-based chemotherapy (chemo), VEGF inhibitor bev, anti-PD-L1 antibody durva and PARP inhibitor olap, in women with newly diagnosed advanced OC. Methods: Eligible pts for this double-blind, randomized, Phase III study must have newly diagnosed, advanced, high-grade epithelial OC and either have completed primary surgery or plan to have interval debulking surgery. Depending on their tumor BRCA mutation (tBRCAm) status (determined by central test), pts will join one of two independent cohorts. Pts in the non-tBRCAm cohort (n~906) will be randomized (1:1:1) before cycle 2 to: a) chemo + bev + placebo (for 6 cycles) followed by bev (15 mg/kg [total 15 months]) + placebo maintenance treatment (IV and tablets); b) chemo + bev + durva (6 cycles) followed by bev + durva (1120 mg q3w [total 15 months]) + placebo (tablets) maintenance treatment; or c) chemo + bev + durva (6 cycles) followed by bev + durva + olap (300 mg bd tablets [24 months]) maintenance treatment. Pts in the open-label tBRCAm cohort (n~150) will receive 6 cycles of chemo + durva followed by durva + olap maintenance therapy, with optional use of bev. The primary endpoint of progression-free survival will be assessed by modified RECIST 1.1. Key secondary endpoints include overall survival, overall response rate and duration of response. Enrollment began in January 2019. Clinical trial information: NCT03737643.

OPINION investigated maintenance olaparib in platinum-sensitive relapsed ovarian cancer patients without a germline BRCAm.• In this primary analysis, median PFS was 9.2 months overall, demonstrating clinical benefit versus historical controls.• Median PFS was prolonged across predefined biomarker subgroups based on BRCAm and HRD status.• The safety profile of maintenance olaparib was generally consistent with previous reports.• Our findings support maintenance olaparib as a standard of care in PSROC, irrespective of BRCAm or HRD status.

Background: In the absence of randomised head-to-head trials, we conducted a population-adjusted indirect treatment comparison (PA-ITC) of phase III trial data to evaluate the relative efficacy and safety of maintenance olaparib and bevacizumab alone and in combination in patients with newly diagnosed, advanced ovarian cancer and a BRCA mutation (BRCAm). Methods: An unanchored PA-ITC was performed on investigator-assessed progression-free survival (PFS) data. Individual patient data from SOLO1 (olaparib versus placebo) and from BRCA-mutated patients in PAOLA-1/ENGOT-ov25 (olaparib plus bevacizumab versus placebo plus bevacizumab) were pooled. Each arm of PAOLA-1 was weighted so that key baseline patient characteristics were similar to the SOLO1 cohort. Analyses were performed in patients with complete baseline data. Weighted Cox regression analysis was used to estimate the comparative efficacy of different maintenance therapy strategies, supplemented by weighted KaplaneMeier analyses. Results: Data from SOLO1 patients (olaparib, n Z 254; placebo, n Z 126) were compared with data from BRCA-mutated PAOLA-1 patients (olaparib plus bevacizumab, n Z 151; placebo plus bevacizumab, n Z 71). Adding bevacizumab to olaparib was associated with a numerical improvement in PFS compared with olaparib alone (hazard ratio [HR] 0.71; 95% confidence interval [CI] 0.45e1.09). Statistically significant improvements in PFS were seen with olaparib alone versus placebo plus bevacizumab (HR 0.48; 95% CI 0.30e0.75), olaparib plus bevacizumab versus placebo (0.23; 0.14e0.34), and placebo plus bevacizumab versus placebo (0.65; 0.43e0.95). Conclusions: Results of this hypothesis-generating PA-ITC analysis support the use of maintenance olaparib alone or with bevacizumab in patients with newly diagnosed, advanced ovarian cancer and a BRCAm.