541P Efficacy of various anticancer agents after failure of maintenance olaparib: A retrospective study

Abstract

maintenance therapy with PARP-inhibitors (PARPi) may alter efficacy of further chemotherapy in advanced epithelial ovarian cancer (aEOC). We conducted a retrospective study to evaluate efficacy of various therapeutic agents in aEOC patients who progressed after maintenance olaparib therapy. we extracted data for patients with BRCA-positive aEOC who progressed after maintenance olaparib therapy from a prospectively maintained institutional database for 2014-2022 years. Using Cox proportional hazards regression model we analyzed the impact of various platinum, non-platinum and antiangiogenic agents on progression-free survival (PFS) and overall survival (OS) of patients after subsequent anticancer therapy. Statistical analysis was done with R and RStudio software. we identified 146 patients who received maintenance olaparib in the specified timeline, of them 61 (41.7%) patients were treated with subsequent chemotherapy and had available outcomes data. Median duration of previous olaparib therapy was 11.5 mo., the drug was administered as maintenance therapy after median of 2 (1-7) lines of anticancer treatment. Median follow-up time post olaparib progression was 13.0 months. Median post progression PFS and OS were 7.2 mo. and 20.0 mo. Results of Cox-regression analysis of PFS and OS are summarized in Table below. Taxanes- and/or bevacizumab-containing therapy was associated with better outcomes compared to other therapeutic options. Administration of anthracyclines (PLD or doxorubicin) had a detrimental impact on PFS and OS.Table: 541PFactorPFSOSHR (95% CI)pHR (95% CI)p>2 prior lines.97 (.54-1.76).345.48 (.19-1.21).124Taxanes0.47 (.25-.86).0140.26 (.07-.89).032Anthracyclines5.7 (2.48-13.12)<.001*2.57 (1.02-6.51).045Gemcitabine1.28 (.64-2.56).4691.15 (.37-3.53).797Pt-agents1.28 (.56-2.91).546.75 (.24-2.31).627Bevacizumab.54 (0.29-0.98).043.46 (.17-1.20).114*remained significant in multifactor analysis. Open table in a new tab *remained significant in multifactor analysis. taxanes and bevacizumab are valuable therapeutic options for post-olaparib treatment. Anthracyclines may be associated with inferior outcomes in this setting. While optimal treatment for patients progressing after PARPi is unknown, our study provides some insights and hypothesis-generating data for further trials.