Mirvetuximab soravtansine-gynx: first antibody/antigen-drug conjugate (ADC) in advanced or recurrent ovarian cancer

Mirvetuximab soravtansine-gynx (MIRV) is a conjugate of a folate receptor alpha (FR alpha)-directed antibody and the maytansinoid microtubule inhibitor, DM4. Accumulating pre-clinical and clinical data supported the safety and anti-tumor activity of MIRV in tumors expressing FR alpha. In 2017, a phase I expansion study reported the first experience of MIRV in FR alpha-positive platinum-resistant ovarian cancer with promising results. However, the phase III FORWARD I study failed to demonstrate a significant benefit of MIRV in FR alpha-positive tumors. On the basis of the data reported from this latter study, MIRV was then explored in the FR alpha-high population only and using a different folate receptor assay. The phase II SORAYA trial supported the adoption of MIRV in this setting. Hence, the US Food and Drug Administration granted accelerated approval of MIRV for patients with FR alpha-positive platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received 1-3 prior systemic treatment regimens. Moreover, the results of the MIRASOL trial showed a significant reduction in the risk of tumor progression or death among patients treated with MIRV versus chemotherapy. VENTANA FOLR1 (FOLR-2.1) was approved as a companion diagnostic test to identify FR alpha patients. MIRV appears to be a significant asset in managing advanced or recurrent ovarian cancer. Further trials are needed to confirm these promising results, even in the neoadjuvant, adjuvant, and maintenance settings.