Mirvetuximab soravtansine has shown activity in biomarker-selected patients with platinum-resistant ovarian cancer, according to study results published in the Journal of Clinical Oncology.
About one-third of patients with previously treated, FRα-high, platinum-resistant ovarian cancer responded to mirvetuximab soravtansine. Response rates were similar regardless of prior therapy.
Researchers tested mirvetuximab soravtansine in the phase 2 SORAYA trial (ClinicalTrials.gov Identifier: NCT04296890). The trial enrolled patients with FRα-high, platinum-resistant ovarian cancer who had received 1-3 prior therapies, including bevacizumab.
The 105 evaluable patients received mirvetuximab soravtansine at 6 mg/kg once every 3 weeks until disease progression, unacceptable toxicity, withdrawal, or death. The median follow-up was 13.4 months.
The investigator-assessed objective response rate (ORR) was 32.4%, which included 5 complete responses and 29 partial responses. According to the researchers, this ORR is “more than double the ORR of single-agent chemotherapies reported in prior trials” of platinum-resistant ovarian cancer.
Responses were seen regardless of how many prior treatments patients had received and whether or not they had prior PARP inhibitor therapy. The ORR was 35.3% in patients with 1-2 prior lines of therapy and 30.2% in patients with 3 prior lines of therapy. The ORR was 38.0% in patients with prior PARP inhibitor exposure and 27.5% in patients without prior PARP inhibitor exposure.
The median duration of response was 6.9 months in the overall cohort. It was 5.9 months in patients with 1-2 prior lines of therapy, 7.4 months in patients with 3 prior lines of therapy, 5.7 months in patients with prior PARP inhibitor treatment, and 6.4 months in patients without prior PARP inhibitor treatment.
The most common treatment-related adverse events (TRAEs) of all grades were blurred vision (41%), keratopathy (29%), and nausea (29%). TRAEs led to dose delays in 33% of patients, dose reductions in 20%, and discontinuations in 9%.
“Given the lack of effective therapies and poor prognosis for patients in this setting, the findings reported here underscore the potential for MIRV [mirvetuximab soravtansine] to become a biomarker-driven, standard-of-care option in this difficult-to-treat population,” the researchers concluded.
Disclosures: This research was supported by ImmunoGen, Inc. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Matulonis UA, Lorusso D, Oaknin A, et al. Efficacy and safety of mirvetuximab soravtansine in patients with platinum-resistant ovarian cancer with high folate receptor alpha expression: Results from the SORAYA study. J Clin Oncol. Published online January 30, 2023. doi:10.1200/JCO.22.01900