BGCS—ASM 2025 London Publication of Abstracts

Background/Objectives: Presented is the final analysis on overall survival (OS) from the phase-3 MIRASOL trial of FRpositive, platinum-resistant ovarian cancer (PROC) patients treated with mirvetuximab soravtansine (MIRV) versus investigator's choice chemotherapy (ICC).Methods: Patients with 1-3 prior lines of therapy and highgrade serous PROC with high FR-expression (75% of cells/ PS2+ staining intensity) were randomized 1:1 to receive MIRV or ICC.Primary endpoint was progression-free survival (PFS) by the investigator.Secondary endpoints included OS and objective response rate (ORR) by investigator.Further endpoints included safety and tolerability.Results: At data cut-off (September 26, 2024) median follow-up was 30.5 months for the intent-to-treat population (MIRV, n = 227; ICC, n = 226).Median PFS was 5.59 months (95% CI, 4.34-5.88)for MIRV and 3.98 months (95% CI, 2.86-4.47)for ICC (HR 0.63 [95% CI, 0.513-0.785]).Median OS was 16.85 months (95% Confidence interval [CI], 14.36-19.78)for MIRV and 13.34 months (95% CI, 11.37-15.15)for ICC (Hazard ratio [HR] 0.68 [95% CI, 0.534-0.840]).ORR was 41.9% for MIRV and 15.9% for ICC (Odds Ratio 3.75 [95% CI, 2.400-5.852]).No new safety signals were observed.Among patients in the safety population (MIRV, n = 218; ICC, n = 207), compared with ICC, MIRV was associated with lower rates of grade 3 treatmentemergent AEs (TEAEs) (44% vs. 55%), serious AEs (25% vs. 33%), and discontinuations (11 % vs. 15%).No deaths from treatmentrelated TEAEs occurred in the MIRV arm.Conclusions: MIRV treatment continued to demonstrate superior OS benefit compared to ICC with a 32% risk reduction of death, and a well characterized safety profile.