The treatment is indicated for patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancers.
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Trial Name: A Study 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 (MIRASOL)
ClinicalTrials.gov ID: NCT04209855
Sponsor: ImmunoGen, Inc.
Completion Date (Estimated): April 2024
The FDA has approved mirvetuximab soravtansine-gynx (Elahere; AbbVie, ImmunoGen Inc) for the treatment of folate receptor alpha (FRα)-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal adult cancer patients who received 3 prior therapies. According to experts, patients with these cancers often present with late-stage disease, undergo surgery, and are then treated with a subsequent platinum-based chemotherapy but may become resistant.1
Mirvetuximab soravtansine is a first-in-class antibody-drug conjugate that compromises the FRα-binding antibody, cleavable linker, and the maytansinoid payload DM4, designed to kill the targeted cancer cells. Previously, mirvetuximab soravtansine was granted an FDA accelerated approval in November 2022.
The FDA approval comes are positive results from the phase 3 MIRASOL (NCT04209855) trial, and it is indicated for adult patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received 1 to 3 prior systemic treatment regimens.1
"The full FDA approval of [mirvetuximab soravtansine] for eligible patients with ovarian cancer represents the culmination of years of work...[mirvetuximab soravtansine] is the first and only ADC approved in the U[United States]S for this difficult-to-treat malignancy," said Roopal Thakkar, MD, senior vice president, chief medical officer of global therapeutics at AbbVie, in a press release.1
MIRASOL is a randomized, open-label phase 3 trial that enrolled 453 patients with advanced high-grade epithelial ovarian, primary peritoneal, or fallopian tube cancers with high FRα expression to evaluate the efficacy of mirvetuximab soravtansine compared with investigator’s choice of chemotherapy (paclitaxel, peglyated liposomal doxorubicin [PLD], or topotecan). Each patient had been previously treated with at least 1 line of therapy, with 14% receiving 1 prior line of therapy, 39% receiving 2, and 47% receiving 3.1,2
Patients were randomly assigned to receive either 6mg/kg of mirvetuximab soravtansine every 3 weeks based on their adjusted ideal body weight; or 80 mg/m2 of paclitaxel once weekly within a 4-week cycle, 40 mg/m2 of PLD every 4 weeks, or 4 mg/m2 of topotecan either on days 1, 8, and 15 every 4 weeks for 5 consecutive days. The primary endpoint of the trial was progression-free survival (PFS) by investigator assessment, and key secondary endpoints included objective response rate (ORR) and overall survival (OS).1,2
The findings indicated that paclitaxel as the most commonly chosen chemotherapy (41%), followed by PLD (36%) and topotecan (23%). Treatment with mirvetuximab soravtansine had improved OS, with a 33% reduction in the risk of death compared with the chemotherapy arm (Hazard ratio [HR]:0.67; 95% confidence interval [CI]: 0.50, 0.88; p = .0046). In addition, PFS was also improved in the mirvetuximab soravtansine arm, with patients having a 35% reduction in the risk of tumor or cancer progression compared with chemotherapy (HR: 0.65; 95% CI: 0.52, 0.81; p < .0001).1
The most common adverse events (AEs)—including laboratory abnormalities—reported by patients included increases in aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase as well as decreases in lymphocytes, platelets, magnesium, hemoglobin, leukocytes, vomiting, albumin, appetite, and neutrophils. Other AEs included fatigue, blurred vision, nausea, diarrhea, abdominal pain, keratopathy, peripheral neuropathy, musculoskeletal pain, dry eye, constipation, and vomiting.1
"As the first treatment to show a statistically significant overall survival benefit in patients with platinum-resistant ovarian cancer, [mirvetuximab soravtansine] provides an effective new option for patients with FRα-positive tumors. These patients previously had very limited options and [mirvetuximab soravtansine] changes that," said MIRASOL principal investigator Kathleen Moore, deputy director, associate director of clinical research at the Stephenson Cancer Center of The University of Oklahoma, in the press release.1
