In a phase 3 clinical trial, the antibody drug conjugate targeting folate receptor-alpha, mirvetuximab soravtansine demonstrated benefits to progression-free survival and overall survival for patients with platinum-resistant ovarian cancer, when compared to investigator’s choice of chemotherapy.

The initial report from the phase 3 MIRASOL (GOG 3045/ENGOT-ov55) study were presented by Kathleen Moore, MD, Stephenson Oklahoma Cancer Center at the University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, at the 2023 ASCO Annual Meeting on Sunday, June 4, 2023 in Chicago, Illinois.

This trial enrolled 453 patients with platinum-resistant ovarian cancer and high folate receptor-alpha expression who had previously received ≥3 lines of therapy. Patients were randomized on a 1-to-1 basis to receive either 6 mg/kg of mirvetuximab soravtansine on Day 1 of a 21-day cycle (n = 227), or investigators choice of chemotherapy (paclitaxel, pegylated liposomal doxorubicin, or topotecan; n = 226). The primary end point was progression-free survival (PFS), with objective response rate (ORR), overall survival (OS), and patient reported outcomes at secondary end points. Safety and tolerability were other end points.

At the data cutoff date of arch 6, 2023, the median follow-up duration was 13.1 months. The study met its primary and secondary end points, with statistically significant improvements in PFS, ORR, and OS. The safety profile of mirvetuximab soravtansine was consistent with previous reports, including primarily low-grade ocular and gastrointestinal events. When compared to the investigator’s choice of chemotherapy arm, mirvetuximab soravtansine had less instances of grade ≥3 treatment-emergent adverse events, serious adverse events, and discontinuations due to treatment-emergent adverse events.

As the Dr Moore and coauthors wrote, “the efficacy data, along with the well-characterized safety profile, position [mirvetuximab soravtansine] as a new, standard of care” for patients with folate receptor-alpha positive, platinum-resistant ovarian cancer.

Source:

Moore KN, Angelergues A, Konecny GE, et al. Phase III MIRASOL (GOG 3045/ENGOT-ov55) study: Initial report of mirvetuximab soravtansine vs. investigator's choice of chemotherapy in platinum-resistant, advanced high-grade epithelial ovarian, primary peritoneal, or fallopian tube cancers with high folate receptor-alpha expression. Presented at 2023 ASCO Annual Meeting; June 2-6, 2023; Chicago, IL. Abstract LBA5507