757P - Sustained long-term responders to niraparib maintenance in recurrent platinum-sensitive high-grade ovarian cancer (PSROC): A subanalysis of the GEICO-88R study

Background

GEICO-88R assessed the real-world use of niraparib (NIR) as maintenance in patients (pts) with PSROC (Cueva, EJC 2023). A subanalysis of sustained long-term responders (SLTR), NIR exposure ≥24 months (m), was conducted.

Methods

Across 57 Spanish sites, pts received NIR at fixed 300 mg/day (FSD) or individualized starting dose (ISD). An analysis of SLTR is presented, focusing on pts characteristics, survival, and post-NIR treatments.

Results

Of 316 pts, 61 (19,3%) SLTR were analyzed. 82% were BRCAwt, with median of 2 prior lines and 47.5% with relevant comorbidities. Median NIR initial dose was 200 mg/day. FSD/ISD was initiated in 16 (26.2%) and 45 (73.8%) pts. 66.6% ORR was achieved in pts with pre-NIR measurable disease. With median follow-up of 57 m, mPFS was 47.3 m (95% CI 28.8-NA). mPFS2 and mOS were not reached. Upon analysis, 31 (50.8%) pts remained on NIR, and 42 (68.9%) pts were still alive. 56 (91.8%) / 41 (67.2%) pts were alive at 3 / 5 years. 37.7 % discontinued due to progression, 3.3% toxicity and 4.9% physician/pts decision. One AML was observed. 27 pts (44.3%) had ≥1 post-NIR systemic treatment, in 23 pts (85.1%) was platinum-based. ORR with 1st subsequent line was 33.3%. mPFS of 1st post-NIR line was 7.8 m (95% CI 3.6-17.5). Table: 757P

Baseline patient characteristics

Conclusions

This subanalysis of SLTR to NIR maintenance in real life shows nearly 20% of the total of pts with remarkable benefit (≥24 m). Two thirds of pts are alive at 5 years and mOS is not reached despite being a high-risk population. This subgroup will be compared with non-SLTR to elucidate differences explaining this outstanding benefit.

Clinical trial identification

NCT04546373.

Editorial acknowledgement

Legal entity responsible for the study

Grupo Español de Investigación en Cáncer Ginecológico (GEICO).

Funding

GSK.

Disclosure

J.F. Cueva Banuelos: Financial Interests, Personal, Advisory Board: AstraZeneca, MSD, Novartis; Financial Interests, Personal, Invited Speaker: AstraZeneca, MSD, GSK, Clovis, Pfizer, Novartis, Lilly, Roche, Pierre Fabre, Palex, PharmaMar; Financial Interests, Personal, Other, Attending and accommodation scientific meetings: AstraZeneca, Lilly, MSD. P. Estevez Garcia: Financial Interests, Personal, Advisory Board: PharmaMar, Clovis, GSK, Eisai; Financial Interests, Personal, Invited Speaker: AstraZeneca, MSD, GSK, AstraZeneca, Eisai, PharmaMar; Financial Interests, Institutional, Research Grant: GSK. Y. Garcia Garcia: Financial Interests, Personal, Advisory Board: GSK, Astra-Zeneca, Roche; Financial Interests, Personal, Invited Speaker: GSK, Astra-Zeneca, Roche; Financial Interests, Personal, Other, Congress fees and travel expenses: MSD; Financial Interests, Personal, Other, Congress fees: GSK. C. Salvador Coloma: Financial Interests, Personal, Invited Speaker: GSK, Pfizer, MSD. A. Santaballa Bertran: Financial Interests, Personal, Advisory Board: Clovis, GSK, MSD, Astra; Financial Interests, Personal, Invited Speaker: Clovis, GSK, Astra, MSD. S. Hernando Polo: Financial Interests, Personal, Advisory Board, Advisory board: GSK; Financial Interests, Personal, Advisory Board, Advisory Board: MSD-AstraZeneca, Pfizer; Non-Financial Interests, Principal Investigator, Principal Investigator: GSK. E.M. Guerra Alia: Financial Interests, Institutional, Invited Speaker: PharmaMar; Financial Interests, Personal, Advisory Board: AstraZeneca, MSD, GSK, Roche; Financial Interests, Personal, Invited Speaker: Clovis, Eisai, AstraZeneca, MSD; Financial Interests, Institutional, Other, Travel Expenses: GSK. J. Fuentes Pradera: Financial Interests, Personal, Advisory Board: Roche, AstraZeneca, MSD, Takeda, Sanofi; Financial Interests, Personal, Invited Speaker: Pfizer; Financial Interests, Institutional, Local PI: Gilead, Roche, Daiichi, BioAtla. A. González-Martín: Financial Interests, Personal, Advisory Board: Amgen, AstraZeneca, Clovis, GSK, Genmab, Alkermes, Sutro, Roche, Sotio, PharmaMar, Oncoinvent, Novartis, Mersana, MSD, Macrogenics, Eisai, Inmunogen, Regeneron, HederaDx, Illumina, Tubulis; Financial Interests, Personal, Invited Speaker: GSK, Astra Zeneca, Clovis, Roche, Novocure, MSD, Takeda, Zaylab; Financial Interests, Institutional, Coordinating PI, PI of ANITA trial: GSK, Roche; Financial Interests, Personal, Steering Committee Member, Member of ENGOT ov43-SC: MSD; Financial Interests, Institutional, Coordinating PI, ENGOT PI of EPIK-O trial: Novartis; Financial Interests, Institutional, Coordinating PI, ENGOT PI of AVB-500 phase III trial: ARAVIVE. All other authors have declared no conflicts of interest.