Abstract A05: Maintenance therapy for platinum-sensitive (PS) recurrent ovarian cancer (rOC): What are we actually choosing?

Abstract

Abstract Background: Treatment for platinum-sensitive (PS) recurrent ovarian cancer (rOC) patients generally consists of retreatment with platinum-based chemotherapy. Maintenance therapy with a targeted agent can extend the interval before progression. Patients with a somatic or germline BRCA mutation (BRCAm) have a greater clinical benefit with maintenance PARPi compared to BRCA wild-type (BRCAwt). Data have shown that ~50% of patients eligible for maintenance therapy do not receive it and variation in the type of maintenance therapy prescribed (BEV vs. PARPi) exists both nationally and within institutions. The objective of this study was to analyze the utilization of maintenance therapy in PS rOC at a large, high-volume academic institution. Methods: This retrospective cohort study evaluated PS rOC patients seen at the University of Alabama at Birmingham (UAB) who completed 2nd line or greater platinum-based chemotherapy for 3-8 cycles since March 27, 2017 (date of FDA approval for PARPi maintenance). Medical records on all patients were reviewed from 9/2018-2/2019 to capture a recent representative sample. Percent of patients and what type of maintenance therapy they received after platinum-based treatment were assessed. The difference in BRCA status between these groups was evaluated. Progression-free survival (PFS) was compared between those who received maintenance therapy and those that did not. PFS was defined as the date of initiation of platinum-based chemotherapy until progression of disease or death regardless of whether or not they were on maintenance therapy (based on PFS definition in BEV maintenance phase III clinical trials). Results: There were 61 PS rOC patients seen during this time period who were eligible for maintenance therapy. 72% received maintenance therapy: 86% (n=38) received PARPi and 14% (n=6) received BEV. PFS following platinum-based chemotherapy with at least one dose of maintenance therapy was 13.4m (6.5-23.6) vs. 11.4m (7.5-27.0) with no maintenance therapy. Germline and somatic BRCA status were known in ~75% of the cases. 60% (9/15) of the patients with a BRCAm (somatic or germline) received maintenance therapy; all patients received a PARPi. PFS in these patients was 17.5m (15.6-19.0) vs. 10.7m (8.0-27.0) with no maintenance therapy. Conclusions: Consistent with randomized control trials, maintenance therapy prolonged PFS in PS rOC patients, which was more pronounced in BRCAm patients who received a PARPi, although not statistically significant in our small cohort of patients. At our institution, >50% of patients who were eligible for maintenance therapy received it, which is higher than data obtained from national databases. While 30% of the patients did not receive maintenance therapy, this could have been based on a multitude of factors including toxicity, degree of benefit, cost, etc. Only 60% of the patients with known BRCAm received maintenance PARPi, which warrants further investigation into the potential barriers that exist. Citation Format: Hannah Beer, Jaclyn Arquiette, Angelina I. Londono, Mckenzie Foxall, Charles A. Leath III, Rebecca C. Arend. Maintenance therapy for platinum-sensitive (PS) recurrent ovarian cancer (rOC): What are we actually choosing? [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A05.