Posted: Tuesday, May 27, 2025
Mirvetuximab soravtansine-gynx showed a statistically significant and clinically meaningful overall survival benefit over chemotherapy in patients with FRα-positive, platinum-resistant ovarian cancer, according to results from the phase III MIRASOL trial. Final analysis from the MIRASOL study was presented by Toon Van Gorp, MD, PhD, of the University Hospital Leuven Kefir Cancer Institute in Belgium, at the 2025 Society of Gynecologic Oncology (SGO) Annual Meeting on Women’s Cancer.
The global, confirmatory MIRASOL trial included patients with FRα-positive, platinum-resistant ovarian cancer (platinum-free interval of at least 6 months) and high-grade serous histology who had received one to three prior lines of therapy. Patients were randomly assigned to received mirvetuximab soravtansine at 6 mg/kg every 3 weeks or investigator’s choice of chemotherapy.
The final analysis showed a median progression-free survival of 5.59 months with mirvetuximab soravtansine compared with 3.98 months with chemotherapy (hazard ratio [HR] = 0.63; 95% confidence interval [CI] = 0.51–0.79; P < .0001). The objective response rate in the mirvetuximab soravtansine arm was 41.9% compared with 15.9% in the chemotherapy arm; the median durations of response were 6.93 months and 4.44 months, respectively.
The median overall survival at the final analysis was 16.85 months with mirvetuximab soravtansine compared with 13.34 months with chemotherapy (HR = 0.68; 95% CI = 0.54–0.84; P = .0004). The 1-year overall survival rate was 65% with mirvetuximab soravtansine vs 56% with chemotherapy.
Further, the rates of grade 3 or higher treatment-emergent adverse events (TEAEs), serious events, and TEAEs leading to discontinuation were higher in the chemotherapy arm than in the mirvetuximab soravtansine arm. No new safety signals were seen in the final analysis.
The FDA approved mirvetuximab soravtansine for the treatment of previously treated adult patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer based on earlier results from the MIRASOL trial. The final analysis was presented after a median follow-up of 30.5 months, which is considered one of the longest follow-up times of any global study in this patient population.
“Mirvetuximab soravtansine’s clinical efficacy along with its well-characterized safety profile supports mirvetuximab soravtansine as the standard of care for patients with FRα-positive, platinum-resistant ovarian cancer,” Dr. Gorp noted in the SGO presentation.
SGO Annual Meeting on Women’s Cancer 2025