Olaparib Outcomes in Patients with BRCA 1-2 Mutated, Platinum-Sensitive, Recurrent Ovarian Cancer in Croatia: A Retrospective Noninterventional Study

Our objective was to assess the safety and efficacy of olaparib in maintenance therapy of BRCA 1-2 mutated, platinum-sensitive, recurrent ovarian carcinoma after the partial or complete response to the second or further lines platinum-based chemotherapy in a real-world setting. We performed a multicenter, real-world observational population-based cohort study on the whole population of Croatian patients initiated to olaparib maintenance therapy between 2016 and 2020. The primary endpoints were progression-free survival and the discontinuation of treatment because of adverse events. We enrolled the total population of 69 patients with the median (interquartile range; IQR) age of 53 (48-59), 56 (81%) of them with BRCA1 mutation. The median (IQR) follow-up was 16 (9-25) months. Treatment had to be discontinued because of toxicity in 2 (3%) and temporarily interrupted in 14 (20%), while dose was reduced because of toxicity in 18 (26%) of patients. Toxicity of any grade was observed in 61 (88%) patients and toxicity of grade 3 or 4 in 12 (17%). Median progression-free survival was 21 (95% CI 16-not calculable) months from the introduction of olaparib, and the median overall survival was not reached. Our study confirmed efficacy and safety of olaparib as the maintenance therapy of BRCA 1-2 mutated, platinum-sensitive, recurrent ovarian carcinoma. We observed the real-world efficacy and safety comparable to those observed in the randomized controlled trials. We found the interesting observation of better efficacy of 300 mg tablets, compared to 400 mg capsules, an issue that should be addressed on much larger real-world populations.