Olaparib maintenance therapy after frontline chemotherapy in patients with BRCA-mutated ovarian cancer: real-world results in expanded access program

Introduction. Olaparib is the only PARP inhibitor approved in Russia for the maintenance therapy for BRCA-positive ovarian cancer after frontline chemotherapy. We conducted a real-world analysis of olaparib efficacy and safety for this indication.Aim. To assess the efficacy of PARP inhibitors in real-world clinical practice.Materials and methods. Patients with stage III-IV BRCA-mutated ovarian cancer who received olaparib maintenance therapy in expanded access program in 03.2019-12.2020 timeframe. Briefly, key inclusion criteria were: serous or endometrioid highgrade ovarian cancer; pathogenic BRCA1/2 mutation; primary or interval debulking; complete or partial response to frontline platinum-based therapy. Olaparib was administered as tablets (300 mg BID) up to 2-years, disease progression or unacceptable toxicity, whichever occurred first. The primary endpoint of the study was progression-free survival (PFS), overall survival (OS) and safety were key secondary endpoints. Statistical analysis was done with R and RStudio software.Results and discussion. 23 patients were enrolled. Median age was 49 years, all patients had high-grade serous adenocarcinoma histology. Complete debulking at primary or interval surgery was achieved in 30% of patients. With median follow-up time equal to 22 months, median PFS and OS were not reached. The 2-year PFS and OS were 65 and 84%, respectively. Grade 3-4 adverse events was detected in 7 (30.4%) patients.Conclusion. Our results supports high efficacy of olaparib in real clinical practice setting reported in the SOLO1 trial.