Ursula A. Matulonis, MD, spoke about the motivation behind the phase 3 SORAYA trial investigating mirvetuximab soravtansine in patients with folate receptor α–high platinum-resistant ovarian cancer.
At the 2022 Annual Global Meeting of the International Gynecologic Cancer Society, CancerNetwork® spoke with Ursula A. Matulonis, MD, chief of the Division of Gynecologic Oncology, Brock-Wilson Family Chair, and institute physician at Dana-Farber Cancer Institute as well as professor of medicine at Harvard Medical School in Boston, Massachusetts, about the reasoning behind the phase 3 SORAYA trial (NCT04296890), which investigated mirvetuximab soravtansine in patients with folate receptor (FR) α–high platinum-resistant ovarian cancer.1
Women with advanced platinum-resistant ovarian cancer have very limited options. Most of them have received bevacizumab [Avastin] as part of their upfront or recurrence regimen. They have single-agent, non–platinum-based chemotherapy as options, and these range [in efficacy] from response rates of 4% up to 12% or 13%. The durations of response are quite short, and that’s measured in weeks. There has not been an FDA approval in the platinum-resistant setting since 2014.2 The SOROYA study is a very positive trial and mirvetuximab soravtansine is a very active and promising agent.
Mirvetuximab soravtansine is an antibody-drug conjugate. It targets the folate receptor 1, or FR- α, which is present in around 35% to 40% of high-grade serous ovarian cancer. The antibody-drug conjugate is an antibody to FR-α and is linked to a toxin called DM4, which is a maytansinoids toxin. It’s an anti-microtubule drug and this drug has been in clinical testing for a number of years. SORAYA is a phase 3 study, although it’s not a randomized and it’s a single-arm trial. This is testing the effectiveness of mirvetuximab soravtansine as a single agent at a dose of 6 mg/kg using the ideal body weight in patients with platinum-resistant, high-grade serous ovarian cancer.
To get into the SORAYA study, patients had to have platinum-resistant, high-grade serous ovarian cancer and at least 1 and up to 3 prior lines of treatment. All patients had to receive prior bevacizumab and their cancer had to demonstrate FR- α with high membrane staining using the IHC PS [immunohistochemistry performance score] 2 scoring, meaning that 75% or higher of the cancer cells had to be positive for FR- α with 2 plus or higher staining intensity.