Clinical experience with rucaparib after prior PARPi treatment: A subanalysis from the rucaparib access program in Spain by GEICO.

Abstract

e17598 Background: Rucaparib is a PARP inhibitor (PARPi) approved as maintenance therapy for platinum (Pt)-sensitive recurrent high-grade ovarian cancer (HGOC), and as treatment for BRCA-mutant HGOC patients. To date, there is little evidence about the efficacy and safety of rucaparib after prior exposure to PARPi. This subanalysis aims to describe the patients’ characteristics and treatment outcomes with rucaparib in women who were included in the rucaparib early access program (RAP) in Spain and had received a prior PARPi. Methods: A retrospective study was conducted by GEICO at 22 hospitals in Spain to analyze data of 51 women treated within the RAP (600 mg BID). Adult women with HGOC, fallopian tube, or primary peritoneal cancer, who had received at least one prior PARPi before rucaparib were analyzed. Patients’ characteristics, medical history, safety, efficacy, and dosing data were collected. Results: A total of 14 women, with a median age of 63 years old (42-78) were included in this subanalysis. Of them, 92.9% were diagnosed of epithelial ovarian cancer and 78.6% had mutations in BRCA1/ 2 genes. The median number of lines before rucaparib was 5 (3-8), while the number of lines before the first PARPi was 3 (2-5). Except for one woman who had received 2 prior PARPis before rucaparib, the others had received just 1. Most patients were given olaparib as the first PARPi (n = 12, 85.8%), while niraparib was the initial PARPi in the remaining cases (n = 2, 14.3%). The outcomes of the treatment with rucaparib in these patients are outlined in table 1. Rucaparib was given as maintenance therapy in 1 patient and as treatment in 13 patients, 12 of them being Pt-resistant. The progression-free survival (PFS) ranged from 0.23 to 9.12 months. Adverse events (AE) of any grade were detected in 78.6% of patients, whereas AE of grade ≥3 affected 28.6% of women. Rucaparib dose was interrupted in 57.1% and reduced in 42.9% of patients. Only 1 patient discontinued rucaparib due to toxicity. No new safety signals were detected. Conclusions: This is one of the first real-word studies reporting the use of rucaparib after treatment with another PARPi. Even in these heavily pre-treated patients who had received prior PARPi, rucaparib efficacy has been notable in some cases, and its safety profile is consistent with that reported in previous clinical trials. Future studies should focus on the selection of patients who could benefit from rucaparib after prior PARPi exposure. [Table: see text]