e18710 Background: With the advent of poly(ADP-ribose) polymerase inhibitors (PARPi), options for first-line (1L) maintenance therapy in ovarian cancer (OC) have evolved in the US. This study described the use of 1L maintenance and assessed predictors of 1L maintenance use among PARPi-eligible patients (pts) with OC in a real-world setting. Methods: This retrospective cohort study included pts with newly diagnosed stage III/IV epithelial OC who received 69 cycles of 1L platinum-based chemotherapy (PBC) and primary or interval debulking surgery following neoadjuvant chemotherapy between Jan 1, 2016, and Feb 29, 2020, from the nationwide Flatiron Health electronic health recordderived deidentified database. The end of the last cycle of 1L PBC was defined as the index date. Those pts who started second-line chemotherapy within 2 months of the index date were excluded. Logistic regression was used to analyze variables with regard to 1L maintenance use. Results: In total, 463 pts were included; 21% received maintenance therapy, 79% received active surveillance. Baseline characteristics are shown in the table. Overall maintenance therapy use increased over the study period, from 7.7% to 37.7%. Pts with BRCA wild type were significantly less likely to receive maintenance therapy (odds ratio [OR]: 0.30; 95% CI, 0.160.59) than pts with BRCA mutation. Pts treated in 2018 (OR: 2.73; 95% CI, 1.255.98) and 2019 (OR: 8.78; 95% CI, 4.1518.55) were significantly more likely to receive maintenance therapy than pts treated in 2017. Age, race, practice type, ECOG score, and residual disease status were not significant predictors of 1L maintenance use. Conclusions: Nearly 40% of pts with advanced stage OC received upfront maintenance therapy with an increasing trend over time, particularly in those with biomarker guidance. Research is warranted toward addressing barriers to the appropriate use of maintenance therapy.[Table: see text]
364 Efficacy of niraparib therapy in patients with newly diagnosed advanced ovarian cancer by brcawt status: prima/ENGOT-OV26/GOG-3012 study
