Olaparib as maintenance therapy and salvage therapy in recurrent ovarian cancer: The early experience in Taiwan

Objective: The first Poly (adenosine diphosphate [ADP]-ribose) polymerase inhibitor, olaparib, was approved by Taiwan Food and Drug Administration in June 2018, which was available under a compassionate use program since 2015. This study aims to report the early experience of the effectiveness and adverse effects of olaparib in recurrent ovarian cancer patients in Taiwan. Materials and methods: This retrospective study enrolled patients with recurrent epithelial ovarian and peritoneal cancer who received olaparib as maintenance therapy or salvage therapy between December, 2015 and October, 2019. We observed response rates in the salvage therapy group, and progression-free interval (PFI) in both groups. Results: A total of 20 patients (10 in maintenance and 10 in salvage groups) were enrolled. BRCA status was checked in 18 patients by blood or tumor samples, and 83.3% were mutated (n = 15), including pathological/probable pathological variants in BRCA1 (n = 11), BRCA2 (n = 2), or both BRCA1/BRCA2 (n = 2). In the salvage group, there were two partial responses and two stable diseases, adding up to a clinical benefit rate at 40%. In the maintenance group, median PFI was 20.1 months (range, 1.0–33.1). The median PFI of those with chemotherapy-free interval >12 months was not reached, which was significantly better than those ≤12 months, with median PFI 3.1 months (p = 0.022). The most common grade 3/4 adverse effects in patient with olaparib as monotherapy were neutropenia (30.8%) and fatigue (7.7%). Anemia of grade 1/2 was noted in 76.9%. Conclusion: This real-world experience of olaparib for recurrent ovarian cancer in Taiwan showed efficacy and safety similar to the results of previous clinical trial.