On March 22, 2024, the Food and Drug Administration approved mirvetuximab soravtansine-gynx for adult patients with 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 based on an FDA-approved test. Mirvetuximab soravtansine-gynx previously received accelerated approval for this indication.

Full prescribing information for mirvetuximab soravtansine-gynx will be posted here.

Efficacy was evaluated in Study 0416 (MIRASOL, 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 tumours were positive for FRα expression as determined by the VENTANA FOLR1 (FOLR1-2.1) RxDx Assay.

Patients were randomized (1:1) to receive mirvetuximab soravtansine-gynx 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 post-marketing requirement of the previous accelerated approval for mirvetuximab soravtansine-gynx.

The major efficacy outcome measures were overall survival (OS), investigator-assessed progression-free survival (PFS) and confirmed overall response rate (ORR) per investigator assessment. PFS and ORR were evaluated according to RECIST, version 1.1. Median OS was 16.5 months (95% CI: 14.5, 24.6) in the mirvetuximab soravtansine-gynx arm and 12.7 months (95% CI: 10.9, 14.4) in the chemotherapy arm (Hazard Ratio [HR] 0.67 [95% CI: 0.50, 0.88] p-value 0.0046). Median PFS was 5.6 months (95% CI: 4.3, 5.9) and 4.0 months (95% CI: 2.9, 4.5) (HR 0.65 [95% CI: 0.52, 0.81] p-value <0.0001) for the respective arms. ORR was 42% (95% CI: 36, 49) and 16% (95% CI: 12, 22) (p-value <0.0001), respectively.

The prescribing information 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 (≥ 20%) including laboratory abnormalities were increased aspartate aminotransferase, fatigue, increased alanine aminotransferase, blurred vision, nausea, increased alkaline phosphatase, diarrhoea, abdominal pain, keratopathy, peripheral neuropathy, musculoskeletal pain, decreased lymphocytes, decreased platelets, decreased magnesium, decreased haemoglobin, dry eye, constipation, decreased leukocytes, vomiting, decreased albumin, decreased appetite, and decreased neutrophils.

The recommended mirvetuximab soravtansine-gynx 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. FDA expedited programs are described in the Guidance for Industry: Expedited Programs for Serious Conditions-Drugs and Biologics.

Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System or by calling 1-800-FDA-1088.

Source: FDA