Abstract 47P
Background
Platinum sensitivity may be a dynamic status in HGEOC pts. Currently, higher proportion of platinum-resistant (PR) pts exceeds the predicted median OS of 12 months (m) with an ECOG PS 0-1, and PtRc may be still an option. We aimed at evaluating the efficacy of retreating with platinum to HGEOC pts considered PR based solely on platinum-free interval (PFI) <6 m and exploring clinical and molecular predictive markers.
Methods
This is an ambispective observational, single-institution study that assessed PtRc efficacy in pts for whom last PFI was < 6 m and received non-platinum agents afterward for >1 year. Key clinical characteristics and BRCA mutation (BRCA-mut) data were analyzed from medical charts between 2010 and 2022. Objective response rate (ORR) and median progression-free survival (mPFS) were evaluated in the whole population, and according to BRCA status and prior number of lines.
Results
At time of data cut-off, 58 pts were included in the analysis. Median age was 57 years (IQR 48-63), 96.4% had ECOG <1, 93% had high-grade serous histology and 11 pts (18.9%) harbored tBRCA-mut. Median number of lines prior to PtRc were 6 (IQR 5-7), and median PFI prior to PtRc was 24.8m (IQR 19.7-33.5). Platinum doublets used in PtRc contained: paclitaxel (41.4%), PLD (39.7%), gemcitabine (15.5%); or carboplatin alone (3.4%). In the whole cohort, ORR was 56.9% (95%CI 43.2-69.8) and mPFS was 6.9m (95%CI 5.8-8.3). Improved PFS and ORR were observed in tBRCA-mut compared to BRCA wild type (wt) pts: ORR 81.8% (95%CI 48.2-97.7) vs 51.1% (95%CI 36.0-65.9, p=0.08), mPFS 9.0 vs 6.7m (HR 0.39, 95%CI 0.18-0.85; p=0.02), respectively. According to number lines prior to PtRc (=4 vs >4), ORR was 76% (95%CI 54.9-90.6) vs 42.4% (95%CI 25.5-60.8; p=0.01), and mPFS 7.7m vs 6.7m (HR 0.57, 95%CI 0.32-1.0; p=0.05).
Conclusions
PtRc seemed to be an efficacious therapeutic approach for pts previously classified as PR who had received non-platinum therapies for >1 year, especially for those harboring tBRCA-mut or having received =4 prior lines. These data seem to support the dynamic concept of platinum-sensitivity. Further research is warranted to better select pts for whom PtRc would be an option.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
D. García-Illescas: Non-Financial Interests, Personal, Training: Merck, GSK, LEO Pharma. L. Fariñas Madrid: Non-Financial Interests, Personal, Speaker’s Bureau: AstraZeneca, MSD, Clovis, Roche; Non-Financial Interests, Personal, Advisory Board: GSK, Clovis; Non-Financial Interests, Personal, Other, Travel/accomodation/expenses: AstraZeneca-MSD, Roche, GSK, Ability Pharma. A.A. Valdivia: Non-Financial Interests, Personal, Other, Travel/accommodation expenses: Merck; Non-Financial Interests, Personal, Speaker’s Bureau: Pfizer, Jansen, AstraZeneca. C. Garcia Duran: Non-Financial Interests, Personal, Speaker’s Bureau: GSK, AstraZeneca, MSD. A. Oaknin: Non-Financial Interests, Personal, Advisory Board: Agenus, AstraZeceneca Clovis Oncology, Inc., Corcept Therapeutics, Deciphera Pharmaceutical, Eisai Europe Limited, EMD Serono, Inc., F. Hoffmann-La Roche, GlaxoSmithKline, GOG, Immunogen, Medison Pharma, Merck Sharp & Dohme de España, Mersana Therapeutic; Non-Financial Interests, Personal, Other, Travel/accommodation: Roche, AstraZeneca, PharmaMar, GSK and Clovis. All other authors have declared no conflicts of interest.