Real-world trends of PARPi maintenance treatment uptake and progression-free survival (PFS) in patients (pts) with newly diagnosed advanced ovarian cancer (AOC) in the United States.

Abstract

6580 Background: Since 2018, the FDA has approved 2 PARP inhibitors (PARPi), niraparib and olaparib, for first-line (1L) maintenance therapy for OC. Using real-world population data, we assessed trends of 1L PARPi maintenance treatment uptake and PFS of pts with newly diagnosed AOC. Methods: Pts diagnosed with AOC between January 1, 2017, and June 30, 2021, who completed 1L chemo were identified from the nationwide Flatiron Health electronic health record (EHR)-derived de-identified database. We calculated descriptive statistics describing pt demographics, clinico-pathological characteristics, and 1L treatment patterns. The use of PARPi or active surveillance (AS) was identified during a 120-day period after the last dose of 1L chemo. The end of the 1L treatment identification period was defined as the index date. Time to next treatment was used as a proxy for PFS and was defined as time from the index date to the next therapy, last clinical activity, end of study period, or death. Kaplan-Meier methods and Cox models were used to analyze the PFS endpoint. Results: A total of 705 pts were included in the study; 166 received PARPi monotherapy (PARPi mono) and 539 underwent AS after completion of 1L chemo. Median age was 68 y for AS vs. 65 y for PARPi mono (Table). Median time from last chemo to initiation of PARPi mono was 48.5 d. Median follow-up was 20.6 mo for AS and 10.9 mo for PARPi mono. In the overall group, median PFS (mPFS) was 9.53 mo for AS vs. not reached (NR) for PARPi mono. In those with BRCA mutations ( BRCAm), corresponding mPFS was 11.4 mo vs. NR and for BRCA wild type ( BRCAwt) was 9.1 mo vs. 13.5 mo. On multivariate analysis, 1L PARPi maintenance was an independent predictor for improved PFS when compared to AS in all pts (HR, 0.47; 95% CI, 0.34-0.63), BRCAm (HR, 0.17; 95% CI, 0.07-0.41) and BRCAwt (HR, 0.50; 95% CI, 0.35-0.72). Stage IV at initial diagnosis, no debulking surgery, residual disease, and BRCAwt status were associated with poorer PFS. Trends analysis over the 4-year study period showed PARPi mono use increased from 6% in 2017 to 53% in 2021. Conclusions: This real-world analysis shows that adoption of PARPi mono in the 1L maintenance setting in pts with newly diagnosed AOC has increased to 53% in 2021. PARPi use, when compared with AS, was associated with significantly improved mPFS in both pts with BRCAm and BRCAwt. [Table: see text]