Mirvetuximab soravtansine in the ovarian cancer treatment landscape: influence of prior taxane exposure on outcomes.

Objective: To evaluate prescribing patterns, toxicities, and outcomes among patients receiving mirvetuximab for platinum-resistant ovarian cancer.

Methods: This retrospective study included patients with platinum-resistant ovarian cancer with high folate receptor alpha expression treated with mirvetuximab at a single institution (2018-2023). Patients were categorized based on treatment immediately preceding mirvetuximab: the taxane group received taxane treatment; the non-taxane group received other therapy. An age-matched cohort of platinum-resistant patients not treated with mirvetuximab was included for survival comparison. Statistical analyses included descriptive statistics, Kaplan-Meier curves, log-rank tests, Wilcoxon rank-sum tests, and Cox models.

Results: Forty-one patients received mirvetuximab, with a median of 8 cycles (range; 1-47). Grade ≥3 adverse events included ocular (n = 6; 15%), hematologic (n = 1; 2%), neuropathy (n = 1; 2%), and pneumonitis (n = 1; 2%). Dose reductions and delays occurred in 26 (63%) and 21 (51%) patients, respectively. Mirvetuximab was discontinued in 40 patients (98%), most commonly due to disease progression (n = 35; 88%). Mirvetuximab-treated patients had longer median overall survival from diagnosis compared to the age-matched cohort without mirvetuximab exposure (83.12 vs 52.14 months; HR 0.34, 95% CI 0.18 to 0.64, p < .001). Among patients who received taxane therapy immediately before mirvetuximab (n = 9), average treatment duration was 5 months (9 cycles), with no grade ≥3 neuropathy. In those who received a non-taxane regimen immediately before mirvetuximab (n = 32), average treatment duration was 6 months (8 cycles), with 1 patient (3%) experiencing grade ≥3 neuropathy. Median progression-free survival was similar between groups (5.49 vs 6.28 months; HR 1.30, 95% CI 0.61 to 2.78, p = .50), but overall survival was shorter in the taxane group (11.28 vs 21.02 months; HR 2.47, 95% CI 1.01 to 6.04, p = .048).

Conclusions: Real-world experience with mirvetuximab demonstrated a favorable safety profile and clinical benefit in platinum-resistant ovarian cancer. Taxane therapy immediately preceding mirvetuximab was associated with shorter overall survival but not increased neurotoxicity.