62P A multi-center real-world study of the efficacy and safety of PARP inhibitors in patients with ovarian cancer in Spain

PARP inhibitors (PARPi) have changed the treatment paradigm in ovarian cancer. The objective of this collaborative study among 21 Spanish hospitals is to collect real-world data on the efficacy and safety of ovarian cancer patients treated with PARPi. We conducted a post-authorization observational study with the three available PARP inhibitors (olaparib, niraparib, and rucaparib) in each of their indications. Data were collected from medical records. Clinical-pathological variables, treatment, and survival were recorded. The primary endpoint was progression-free survival (PFS) in the first-line setting and maintenance after platinum-sensitive (PS) relapse. Secondary endpoints included PFS in relevant clinical and molecular subgroups (FIGO stage, type of surgery, BRCAm, HR status). Patients were included from November 2022 to March 2024. Medians and proportions were used for descriptive analysis, and PFS and overall survival (OS) were estimated using Kaplan-Meier method. A total of 391 patients were enrolled in the study, with a median age of 59 years. High-grade serous carcinoma was the most frequent histology (95%). According to FIGO stage at diagnosis, 65% had stage III, and 35% had stage IV. Primary debulking surgery was performed in 50% of the patients (40% optimal), interval debulking surgery in 40%, and 10% were irresectable. Germline BRCA1/2 mutations were present in 25% of the sample. Homologous recombination (HR) testing in first-line was available in 107 patients, and 49% were classified as HR deficient. The median follow-up was 46 months. The table shows the estimated median PFS in both first-line and PS relapse. The hematological adverse events were the most frequent grade 3 events, with an overall discontinuation rate due to adverse events of 10%.Table: 62PMedian PFS in months (95% confidence interval) in the overall cohortFirst-linePlatinum-sensitive relapseNiraparib (n=63)17.0 (4.9-NR)Niraparib (n=153)8.5 (4.0-21.3)Olaparib (n=46)NR (16.3-NR)Olaparib (n=60)19.3 (7.8-NR)Olaparib + bevacizumab (n=10)25.0 (25.0-NR)Rucaparib (n=23)6.5 (3.0-26.8)Bevacizumab (n=76)19.1 (8.0-68.4) Open table in a new tab This multicenter real-world study shows meaningful clinical benefits in PFS with PARPi in advanced ovarian cancer. Safety analyses were consistent with clinical trials.