Real-world effectiveness of first-line maintenance olaparib in women with BRCA-mutated advanced ovarian cancer: U.S. retrospective cohort study.

Abstract

5518 Background: Following cytoreductive surgery and first-line (1L) platinum based chemotherapy, 70% of patients (pts) with newly diagnosed advanced ovarian cancer (AOC) experience relapse within 3 years. 1L maintenance treatment (tx) with olaparib monotherapy, a poly (ADP-ribose) polymerase inhibitor, extended progression free survival in pts with BRCA mutated (BRCAm) AOC in the SOLO-1 (NCT01844986) randomized controlled trial (RCT). We aimed to describe real world characteristics, tx patterns, and clinical outcomes of pts with newly diagnosed, BRCAm AOC. Methods: Data were collected from 457 pts via electronic case report forms in the US. Pt eligibility criteria were positive BRCAm test result between Jan-June 2019 (6 months post 1L olaparib FDA approval), newly diagnosed AOC (no maintenance tx prior to index), aged ≥18 years, no RCT enrollment, no active neoplasia, no prior tx for metastatic/stage IV cancer. Pt follow up was until July 2021. Kaplan-Meier (KM) estimation was used for time to event analysis using progression proxies: Time to subsequent therapy and discontinuation (or death for both) from initiation of 1L maintenance olaparib monotherapy. Results: Pt mean age (±SD) at index was 62 (±10) years, 64% of pts were white and 18% African American; further clinical characteristics are in the table. 95% of pts received ≥1 pharmacological tx. At 1L, 36% of pts (156/433) received maintenance tx after chemotherapy, with 64% of pts (277/433) receiving routine surveillance (no maintenance tx). Olaparib was the most common maintenance tx (67%, 105/156), with 67% of pts (70/105) prescribed olaparib monotherapy. At 24 months, the KM model estimated 91% of pts (95% confidence interval: 82, 96) would not progress to their subsequent therapy, with a median discontinuation of olaparib monotherapy of 25.0 (interquartile range [IQR]: 21.0, not estimable) months, over a median follow-up of 22.0 (IQR: 20.6, 24.0) months. Conclusions: This real world study complements SOLO-1 RCT data by demonstrating prolonged benefit of 1L olaparib in newly diagnosed pts with BRCAm AOC in terms of lower likelihood of progression (tx switch/death). To assess real world tx effectiveness globally, data collection across further eight countries is due to be completed in 2022. [Table: see text]