On March 22, the U.S. Food and Drug Administration (FDA) approved mirvetuximab soravtansine-gynx (Elahere) for adult patients with folate receptor–alpha (FRα)-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, who have received one to three prior systemic treatment regimens. Patients are selected for treatment with mirvetuximab soravtansine based on an FDA-approved test. Mirvetuximab soravtansine previously received accelerated approval for this indication.
MIRASOL/Study 0416
Efficacy was evaluated in Study 0416 (MIRASOL, ClinicalTrials.gov identifier NCT04209855), a multicenter, open-label, active-controlled, randomized, two-arm trial in 453 patients with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer. Patients were permitted to receive up to three prior lines of systemic therapy. The trial enrolled patients whose tumors were positive for FRα expression as determined by the VENTANA FOLR1 (FOLR1-2.1) RxDx Assay. Patients were randomly assigned 1:1 to receive mirvetuximab soravtansine at 6 mg/kg (based on adjusted ideal body weight) as an intravenous infusion every 3 weeks or investigator’s choice of chemotherapy (paclitaxel, pegylated liposomal doxorubicin, or topotecan) until disease progression or unacceptable toxicity. The results from this trial satisfy the postmarketing requirement of the previous accelerated approval for mirvetuximab soravtansine.
The major efficacy outcome measures were overall survival, investigator-assessed progression-free survival, and confirmed overall response rate per investigator assessment. Progression-free survival and overall response rate were evaluated according to Response Evaluation Criteria in Solid Tumors version 1.1. Median overall survival was 16.5 months (95% confidence interval [CI] = 14.5–24.6 months) in the mirvetuximab soravtansine arm and 12.7 months (95% CI = 10.9–14.4 months) in the chemotherapy arm (hazard ratio [HR] = 0.67, 95% CI = 0.50–0.88, P = .0046). Median progression-free survival was 5.6 months (95% CI = 4.3–5.9 months) and 4.0 months (95% CI = 2.9–4.5 months) for the respective arms (HR = 0.65, 95% CI = 0.52–0.81, P < .0001). Overall response rate was 42% (95% CI = 36%–49%) and 16% (95% CI = 12%–22%), respectively (P < .0001).
The prescribing information for mirvetuximab soravtansine contains a Boxed Warning for ocular toxicity, and includes pneumonitis, peripheral neuropathy, and embryo-fetal toxicity under Warnings and Precautions. The most common adverse reactions among patients taking the agent (≥ 20%) including laboratory abnormalities were increased aspartate aminotransferase, fatigue, increased alanine aminotransferase, blurred vision, nausea, increased alkaline phosphatase, diarrhea, abdominal pain, keratopathy, peripheral neuropathy, musculoskeletal pain, decreased lymphocytes, decreased platelets, decreased magnesium, decreased hemoglobin, dry eye, constipation, decreased leukocytes, vomiting, decreased albumin, decreased appetite, and decreased neutrophils.
The recommended mirvetuximab soravtansine dose is 6 mg/kg adjusted ideal body weight administered once every 3 weeks (21-day cycle) as an intravenous infusion until disease progression or unacceptable toxicity.
This application was granted Priority Review.
