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.
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.
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).
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.