MAINTENANCE OLAPARIB IN PLATINUM-SENSITIVE RECURRENT OVARIAN CANCER: A COMPREHENSIVE CANCER CENTRE'S EXPERIENCE

Introduction/Background* The majority of newly diagnosed patients with ovarian cancer respond to platinum-based chemotherapy (ChT). However, most patients eventually relapse and will need subsequent treatment. Olaparib is a poly ADP– ribose polymerase inhibitor that has shown efficacy as maintenance treatment in patients with platinum-sensitive relapsed ovarian cancer. Methodology We retrospectively evaluated patients with platinum-sensitive relapsed ovarian cancer treated with maintenance olaparib (400mg bid, capsules or 300mg bid, tablets), who previously received ≥2 platinum-based ChT regimens and had a partial or complete response to last platinum-based regimen. All patients were BRCA 1/2 mutated (germline and/or somatic). Study endpoints were progression-free survival (PFS), overall survival (OS), overall response rate and adverse events. Result(s)* Between May 2016 and December 2020, 21 patients were treated with olaparib. Median age was 55 years (range 44-69), and all had ECOG ≤1. The majority had an ovary primary tumour location (81.0%) and serous histology (85.7%). Thirteen patients (61.9%) had partial response to most recent platinum-based ChT, and eight (38.1%) had complete response. Median follow-up time was 18.3 months (1.8-60.3), with 13 patients alive. Median PFS was 8.3 months (CI95% 6.0-10.6). Median OS was not reached. Overall response rate was 19.0% (4 complete responses) and 16 patients had stable disease; hence, 95.2% benefited from treatment with olaparib. There were no differences in PFS by number of prior platinum regimens, response to last platinum-based ChT, time-to-progression after penultimate platinum-based ChT (>6-12 vs >12 months) or BRCA mutation type (germline vs somatic). Most adverse events reported were grade 1 or 2 and were mainly nausea and haemathologic toxicity. Grade 3 and 4 adverse events occurred in six (28.6%) patients and were: anaemia, neutropaenia and nausea. Thirteen (61.9%) patients suspended olaparib, 12 (57.1%) due to disease progression and one due to her own will. There were no patients that suspended treatment due to toxicity. Conclusion* Our results confirm the effectiveness and safety of maintenance olaparib in real-world setting. This treatment is feasible in the clinic and well tolerated, with manageable toxicity.