New options for platinum-resistant ovarian cancer: Are we in the right direction?

e17566 Background: Ovarian cancer (OC) is the deadliest gynecologic cancer, often diagnosed in advanced stages. Even with combined strategies in the first line that include cytoreduction and systemic treatments, most cases will relapse and become resistant to platinum (PROC). PROC is a clinical unmet need and, until 2025, there was no treatment with overall survival (OS) benefit. MIRASOL, ROSELLA and KEYNOTE-B96 trials have changed this, showing OS benefit. However, these trials’ criteria do not seem to reflect real patients, raising doubts about their feasibility in clinical practice. This study evaluated the applicability of these trials’ criteria in real-world population. Methods: Cross-sectional study of women with high-grade epithelial OC diagnosed between Jan 2016-Dec 2024 (median follow-up 27.8 months 4.0-108.2) at a comprehensive cancer center. Disease evolution was reviewed, focusing on platinum resistance stage. Cut-off date for the database was Dec 31, 2025. Results: A total of 127 patients were included. At diagnosis, median age was 64 years and the majority did not present BRCA mutations (112, 88.2%), had ECOG-PS ≤2 (119, 93.7%), serous tumors (122, 96.1%) in stage III (65, 51.2%). Twenty-six (20.5%) underwent upfront surgery and 38 (29.9%) achieved complete cytoreduction. All received platinum in first line. Eighteen (14.2%) were primary platinum refractory. In the remaining population (109, 85.8%), median time from diagnosis to platinum resistance was 21.2 months 1.3-82.7. At PROC timepoint (median follow-up 7.9 months 0.5-76.9), 90 (82.6%) women had received two prior platinum-based chemotherapy lines 1 line, 40 (36.7%); 2 lines, 50 (45.9%) and 17 (15.6%) had three lines. Bevacizumab was included up to the third line in 45 (41.3%) patients. In third line, 5 (4.6%) already platinum resistant received paclitaxel monotherapy. Sixteen (14.7%) were unfit for further treatment due to lack of clinical conditions. Per trial criteria, 90 (82.6%) qualified for KEYNOTE-B96 and 45 (41.3%) for ROSELLA; 43 (39.4%) could be accepted for both and 17 (15.6%) for neither. Five (4.6%) patients met MIRASOL clinical criteria — we only had folate receptor alpha (FRα) expression data available in 10; assuming SORAYA high-FRα threshold, 32 (29.4%) would be included. Reviewing these criteria (and excluding patient's comorbidities), tumor histology, primary platinum refractoriness, prior lines of treatment and FRα expression are the main reasons that can rule out a patient — across the entire population (127), 35 (27.6%) would not be eligible. Conclusions: The PROC poor prognosis justifies new therapeutic options. However, despite OS benefit shown in recent trials, a substantial proportion of real-world patients do not meet trials’ criteria and thus cannot benefit from these advances. In future, probably only real-world evidence will address this.