Clinical insights from the rucaparib access program in Spain: A sub-analysis of long-term responders by GEICO.

e17562 Background: Rucaparib is a PARP inhibitor approved for the treatment of high-grade ovarian cancer (HGOC). Clinical trials have demonstrated its benefit both as maintenance therapy (MTN) for platinum (Pt)-sensitive recurrent HGOC, and as treatment (Tx) in BRCA-mutated relapsed or recurrent HGOC patients. Here we analyze real-world data from the rucaparib early access program (RAP) in Spain with focus in the long-term responder patients (LTR). Methods: A retrospective observational study was performed by GEICO at 22 hospitals in Spain that had treated patients within the RAP. Adult women with HGOC, fallopian tube, or primary peritoneal cancer were included and received rucaparib (600 mg BID) in the MTN, Tx Pt-sensitive or Tx Pt-resistant setting. Patients’ characteristics, medical history, safety, efficacy, and dosing data were collected. In this analysis, long-term response was defined as progression-free survival (PFS) ≥12 months for the MTN group and ≥6 months for the Tx group. LTR were stratified based on the rucaparib indication (MTN/Tx). Results: Between July 2020 and February 2021, 51 patients were recruited: 18 received rucaparib as MTN and 33 as Tx. In the MTN group, 6 patients (33.3%) were LTR, with a median age of 65 years (54-79). Of them, 2 patients (33.2%) harbored BRCA or RAD51C mutations. The median number of prior lines was 3 (2-6), being ≥5 in 33.2%, and 50.0% received prior bevacizumab. ECOG PS was ≤1 in all these patients, 66.6% had measurable disease and 50.0% achieved a partial response to prior Pt-based chemotherapy. In the Tx group, 10 patients (30.3%) were LTR, with a median age of 71 years (47-86). All of them harbored BRCA and/or RAD51C mutations. The median number of prior lines was 6 (2-9), with 60.0% receiving ≥5 prior lines, and 50.0% received prior bevacizumab. Regarding Pt-status, 40.0% of patients were Pt-sensitive and 60.0% were Pt-resistant. The ECOG PS was ≥1 in 30.0% of patients and 60.0% had measurable disease. The median PFS of LTR was not achieved in the MTN group and was 10.9 months (95% CI: 7.0-16.7) in the Tx group. Adverse events (AE) of any grade were reported in 66.6% of LTR within the MTN group and in 100.0% within the Tx group, while AE of grade ≥3 occurred in 16.6% and 50.0%, respectively. Rucaparib dose was reduced in 50.0% of LTR in the MTN group and 80.0% in the Tx group. Discontinuation rate due to rucaparib toxicity was 20.0% in the Tx group and there were no discontinuations due to toxicity in the MTN group. No new safety signals were detected. At present, 3 and 1 patients are still receiving rucaparib as MTN and Tx, respectively. Conclusions: A durable response was achieved in a notable proportion of patients, even despite their unfavorable conditions at treatment initiation (heavily pre-treated patients, partial response or resistance to Pt, or high volume of disease). The safety profile of rucaparib in this real-world setting is consistent with that reported in clinical trials.