Mirvetuximab soravtansine

Mirvetuximab soravtansine-gynx (IMGN853) is an antibody-drug conjugate (ADC) formed by a monoclonal antibody (M9346A) that targets folate receptor alpha (FRα), covalently joined by a cleavable disulfide linker to the genotoxic compound DM4 (also known as soravtansine or ravtansine). DM4 is conjugated to the antibody with a drug-to-antibody ratio of 3.5:1.

The antibody component of mirvetuximab soravtansine-gynx binds to FRα, a receptor overexpressed on the surface of epithelial tumor cells, characteristic of ovarian, endometrial, triple-negative breast and non-small-cell lung cancers. After an ADC/receptor complex is formed, mirvetuximab soravtansine-gynx is internalized, and DM4 is released inside the cell. DM4 leads to cell-cycle arrest and apoptosis and is also able to diffuse into neighboring cells and induce further cell death.

On November 2022, the FDA granted accelerated approval to mirvetuximab soravtansine-gynx for the treatment of adult patients with FRα–positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received 1-3 prior systemic treatment regimens. This decision was supported by findings from the phase 3 SORAYA trial (NCT04296890).

Mirvetuximab soravtansine is indicated for the treatment of 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 therapy based on an FDA-approved test.

This indication is approved under accelerated approval based on tumor response rate and durability of response. Continued approval for this indication may be contingent upon verification and description of clinical benefit in a confirmatory trial.