Trends in frontline PARP inhibitor maintenance in advanced epithelial ovarian cancer across the United States.

Abstract

5581 Background: Advanced epithelial ovarian cancer (AEOC) is the fifth commonest cancer mortality among women in the United States. Despite 80% initial treatment response, most recur within two years and succumb from disease. Prolonging disease free interval with maintenance therapy is of interest. Options include Poly-(ADP) ribose polymerase inhibitors (PARPi’s) and Bevacizumab, an anti-angiogenesis agent; eligibility criteria are based on clinical trials. Here we examine national approach to front line maintenance therapy following treatment in AEOC with focus on PARPi use. Methods: Protocol for data collection was IRB approved and institutional IRB approved. A retrospective, observational cohort study using Flatiron Health electronic health record (EHR)-derived, de-identified database patients diagnosed with AEOC between March 2017-June 2020, following FDA approval of PARPi use in AEOC. Demographics were summarized using descriptive statistics by use of maintenance treatment, and associations were tested using ANOVA and Chi-squared tests. Trends in use and type of maintenance therapy were summarized by year. Time trends assessed by Cochran–Armitage tests. Results: 1196 patients met inclusion criteria: Age>18, Stage III-IV, 90-day gap rule, systemic therapy after diagnosis. Majority were >65, White, Stage III with ECOG 0 at diagnosis. Only 31.6% of patients received maintenance after frontline therapy. Single agent PARPi was most used (12.9%), and Olaparib was most used PARPi (57%). Use of maintenance therapy significantly differed by ECOG value at diagnosis (p=.005), region of practice (p=.003), use of surgery (p=<.001) and extent of debulking (p=.002). Maintenance therapy was used more often when ECOG low at diagnosis, optimal debulking achieved and with treatment in the Southern US. Maintenance therapy significantly increased by year (p=<0.001); highest in 2020 (46.9%). Type of maintenance therapy had a significantly different trend by year with PARPi becoming more common (p=<.001). Conclusions: Despite known high rates of response to maintenance PARPi and increased use over time, less than 50% of patients with AEOC receive this regimen. Reasons for low adoption of maintenance PARPi in this population with poor prognosis deserves further investigation. Olaparib, approved for single use in BRCA mutation carriers in the front-line maintenance setting was used more often than Niraparib, approved for all comers. [Table: see text]