Dr Konecny on the MIRASOL trial and Mirvetuximab Soravtansine in FRα+ Platinum-Resistant Ovarian Cancer

Gottfried Konecny, MD, lead clinician, gynecologic oncology, Department of Medicine, University of California, Los Angeles (UCLA) Health, provides insights into the phase 3 MIRASOL trial (Study 0416; NCT04209855), which evaluated mirvetuximab soravtansine-gynx (Elahere) in patients with folate receptor alpha (FRα)–positive, platinum-resistant ovarian cancer.

For this patient population, standard treatments often yield low response rates with short durations of responses, along with significant toxicities, necessitating the exploration of novel therapeutic approaches, Konecny begins.

Based on data from MIRASOL, on March 22, 2024, the FDA granted regular approval to mirvetuximab soravtansine for the treatment of adult patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, who have previously received 1 to 3 systemic treatment regimens.

The primary aim of the MIRASOL study was to assess the efficacy of mirvetuximab soravtansine—an antibody-drug conjugate (ADC) targeting FRα with a potent microtubule inhibitor payload—vs investigator-selected chemotherapy. The trial met its primary end point with mirvetuximab soravtansine eliciting a statistically significant improvement in PFS vs chemotherapy (HR, 0.65; 95% CI, 0.52-0.81; P < .0001). The median PFS was 5.6 months (95% CI, 4.3-5.9) for the ADC vs 4.0 months (95% CI, 2.9-4.5) for investigator’s choice of chemotherapy.

Moreover, Konecny noted that the study yielded favorable outcomes in key secondary end points, including overall survival (OS; HR, 0.67; 95% CI, 0.50-0.88; P = .0046). Of particular importance, treatment with mirvetuximab soravtansine elicited a substantially elevated overall response rate (ORR) at 42% (95% CI, 36%-49%) vs 16% (95% CI, 12%-22%) with chemotherapy (P < .0001). These findings collectively suggest the potential establishment of mirvetuximab soravtansine as a new standard of care for FRα-positive, platinum-resistant ovarian cancer, Konecny says.

Konecny notes that the MIRASOL trial underscores the promising therapeutic potential of mirvetuximab soravtansine in addressing the pressing clinical challenges associated with platinum-resistant recurrent ovarian cancer. The observed improvements in PFS, OS, and ORR signify a significant advancement in the treatment of this subgroup of patients with a challenging disease.

Further exploration and validation of these findings in broader clinical contexts are warranted to fully ascertain the clinical utility and long-term benefits of mirvetuximab soravtansine in the ovarian cancer population, Konecny concludes.