Health Canada Approves Mirvetuximab Soravtansine in FRα+ Ovarian Cancer

Results from the phase 3 MIRASOL trial led to the approval of mirvetuximab soravtansine for patients with FRα+ ovarian cancer.

Mirvetuximab soravtansine-gynx (Elahere) has been approved by Health Canada as an injection for patients with folate receptor-alpha (FRα)–positive platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer, who have received 1 to 3 prior therapies, according to a press release from AbbVie.¹

Results from the phase 3 MIRASOL trial (NCT04209855) led to the approval.² Data showed efficacy improvements in favor of mirvetuximab compared with the investigator’s choice of chemotherapy.

Data in the press release showed a statistically significant overall survival (OS; HR, 0.67; 95% CI, 0.50-0.88; P = .0046) with a 33% reduction in the risk of death, which was found to be meaningful compared with the investigator’s choice arm. The progression-free survival (PFS) HR was 0.65 (95% CI, 0.52-0.81; P <.0001), which showed a 35% reduction in the risk of disease progression.

The overall response rate (ORR) was 42% (95% CI, 35.8%-49.0%) in the mirvetuximab arm and 16% (95% CI, 11.4%-21.4%) in the investigator’s choice arm. A complete response was observed in 5% of patients in the mirvetuximab arm compared with 0% in the chemotherapy arm.

A total of 24% of patients had serious adverse effects in the mirvetuximab arm with the most common being pleural effusion (3%), abdominal pain (3%), intestinal obstruction (2%), ascites (2%), and small intestinal obstruction (2%).

“Platinum-resistant ovarian cancer is a challenging disease with limited effective therapies and a poor prognosis,” said Shannon Salvador, MD, president of the Society of Gynecologic Oncologists of Canada, associate professor at McGill University, and director of the Gynecologic Oncology Subspecialty Residency Program. “This approval marks a critical advancement in the treatment of advanced ovarian cancer. [Mirvetuximab soravtansine] has been shown to extend the survival of patients and offers a much-needed new option for those facing this form of gynecological cancer, which has the lowest survival rate in Canada.”

Updated MIRASOL results were presented at the 2025 Society of Gynecologic Oncology Annual Meeting on Women’s Cancer. Patients were randomly assigned 1:1 and were given either mirvetuximab at 6 mg/kg based on adjusted body weight every 3 weeks or the investigator’s choice of chemotherapy. The primary end point was investigator-assessed PFS, and secondary end points included investigator-assessed ORR, OS, and patient-reported outcomes.

Results showed that at a median follow-up of 30.5 months, the median OS was 16.85 months (95% CI, 14.36-19.78) in the mirvetuximab arm vs 13.34 months (95% CI, 11.37-15.15) in the chemotherapy arm. At the long-term analysis, the median PFS was 5.59 months (95% CI, 4.34-5.88) in the mirvetuximab arm vs 3.98 (95% CI, 2.86-4.47) in the investigator choice arm.

Regarding safety, any grade treatment-emergent adverse effects (TEAEs) occurred in 97% of patients in the mirvetuximab arm compared with 94% in the chemotherapy arm. TEAEs that were grade 3 or higher were observed in 44% vs 55%, and serious TEAEs in 25% vs 33%. A dose delay or hold due to TEAEs was noted in 56% in the mirvetuximab arm and 54% in the chemotherapy arm, with reductions in 35% vs 24%.

The most common all-grade TEAEs in the mirvetuximab arm were blurred vision (43%), keratopathy (33%), dry eye (29%), diarrhea (29%), nausea (27%), and peripheral neuropathy (22%).

“Ovarian cancer poses many unique challenges for women. In addition to vague symptoms and late-stage diagnosis, many patients develop a resistance to current treatments that increases their risk of poor survival outcomes,” Tania Vrionis, chief executive officer of Ovarian Cancer Canada, said in the press release.¹ “The approval of [mirvetuximab soravtansine] in Canada is not only welcome news for women in our community, but also a critically needed update to their care. This decision gives them another treatment option and can help improve outcomes for those who are no longer responding to surgery and chemotherapy.”

In March 2024, mirvetuximab was approved by the FDA in the same indication supported by the MIRASOL trial findings.³

References

1. Health Canada approves Elahere® for certain types of platinum-resistant ovarian cancers. News Release. Abbvie. Accessed September 3, 2025. https://tinyurl.com/4nvs7wyb
2. Van Gorp T, Angelergues A, Konecny G, et al. Final overall survival analysis among patients with FRα-positive, platinum-resistant ovarian cancer (PROC) treated with mirvetuximab soravtansine (MIRV) vs investigator’s choice chemotherapy (ICC) in the phase 3 MIRASOL (GOG 3045/ENGOT-ov55) study. Presented at: 2025 SGO Annual Meeting on Women’s Cancer; March 14-17, 2025; Seattle, WA. Abstract 939696.
3. FDA approves mirvetuximab soravtansine-gynx for FRα positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer. News release. FDA. March 22, 2024. Accessed September 3, 2025. https://tinyurl.com/2apx6e5s