As reported in the Journal of Clinical Oncology by Ursula A. Matulonis, MD, and colleagues, results from the phase II SORAYA study showed activity of mirvetuximab soravtansine-gynx, an antibody-drug conjugate targeting folate receptor alpha (FRα), in patients with platinum-resistant ovarian cancer and high FRα expression.
The study supported the November 2022 accelerated approval of the agent for treatment of patients with FRα-positive, platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received one to three prior systemic treatments.
![Ursula A. Matulonis, MD](/media/14019902/29-matulonis.jpg)
Ursula A. Matulonis, MD
Study Details
In the study, 106 patients from sites in 11 countries were enrolled between June 2020 and May 2021 and received mirvetuximab soravtansine at 6 mg/kg every 3 weeks until progressive disease or unacceptable toxicity. Patients had to have received one to three prior therapies, including bevacizumab. About 51% of patients had received three prior lines of therapy, and 48% had received prior poly (ADP-ribose) polymerase (PARP) inhibitor treatment.
The primary endpoint was investigator-assessed confirmed objective response rate.
Responses
Median follow-up was 13.4 months. Among 105 patients evaluable for response, objective response was observed in 34 patients (32.4%, 95% confidence interval [CI] = 23.6%–42.2%), including complete response in 5 (4.8%). An additional 48 patients (45.7%) had stable disease. The disease control rate (including objective responses and stable disease of ≥ 12 weeks) was 51.4%. A total of 75 patients (71.4%) exhibited tumor reduction.
Median duration of response was 6.9 months (95% CI = 5.6–9.7 months). Median progression-free survival was 4.3 months (95% CI = 3.7–5.2 months). Median overall survival was 13.8 months (95% CI = 12.0 months to not reached) with 46% of events reported.
Objective response rates were 35.3% (95% CI = 22.4%–49.9%) among patients with one or two prior lines of therapy, 30.2% (95% CI = 18.3%–44.3%) among those with three prior lines, 38.0% (95% CI = 24.7%–52.8%) among those with prior PARP inhibitor treatment, and 27.5% (95% CI = 15.9%–41.7%) among those who had not received prior PARP inhibitor treatment.
Among 96 patients assessed by blinded independent review committee, objective response was observed in 29 (30.2%, 95% CI = 21.3%–40.4%), with compete response in 6 (6.3%). Median response duration was not reached (95% CI = 5.0 months to not reached). Median progression-free survival was 5.5 months (95% CI = 3.8–6.9 months).
KEY POINTS
- Objective response was observed in 32.4% of patients.
- Objective response was observed in 35.3% of patients with one or two prior lines of therapy and 30.2% of those with three prior lines.
Adverse Events
Among 106 patients in the safety population, the most common treatment-related adverse events of any grade were blurred vision (41%), keratopathy (29%), nausea (29%), and dry eye (25%). Treatment-related grade 3 or 4 adverse events occurred in 29% of patients (grade 4 in 1%), with the most common being keratopathy (9%) and blurred vision (6%). Treatment-related peripheral neuropathy occurred in 18% of patients (all grade 1 or 2).
Serious treatment-related adverse events occurred in 11% of patients. Treatment-related adverse events led to dose delay, dose reduction, and treatment discontinuation in 33%, 20%, and 9% of patients, respectively.
The investigators concluded, “Mirvetuximab soravtansine demonstrated consistent clinically meaningful antitumor activity and favorable tolerability and safety in patients with FRα-high platinum-resistant ovarian cancer who had received up to three prior therapies, including bevacizumab, representing an important advance for this biomarker-selected population.”
Dr. Matulonis, of Dana-Farber Cancer Institute, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was funded by ImmunoGen, Inc. For full disclosures of the study authors, visit ascopubs.org.