Ursula A. Matulonis, MD, spoke about the phase 3 SORAYA trial and how it helped lead to the approval of mirvetuximab soravtansine in folate receptor-α–positive platinum-resistant ovarian cancer.
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 a professor of medicine at Harvard Medical School in Boston, Massachusetts, about the recent approval of mirvetuximab soravtansine-gynx (Elahere) for patients with folate receptor-α (FR-α)–positive platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have been treated with 1 to 3 lines of prior therapy.1 The accelerated approval was based on the results of the phase 3 SORAYA trial (NCT04296890), where patients were treated with mirvetuximab monotherapy.2
In the trial, patients had an overall response rate of 32.4% in the overall patient population, with a complete response rate of 4.8%, a partial response rate of 27.6%, and 45.7% had stable disease. Additionally, the median duration of response was 6.9 months, and the disease control rate was 51.4%, with a reduction in tumor size by 71.4%.
The accelerated FDA approval of mirvetuximab soravtansine, which is an antibody-drug conjugate [ADC], is the first ADC approved for ovarian cancer. The ADC targets FR-α, and it’s linked to DM4, which is an anti-tubulin drug. The approval is for patients who have FR-α–positive, high-grade serous ovarian cancer who have received up to 3 prior lines of treatment. The FR-α positivity is defined by the companion diagnostic approved by the FDA, showing that 75% or higher of cancer cells have to be at least 2-plus or higher staining, positive for FR-α.
The tissue we found through other studies, does not have to be a fresh biopsy, but it can be archival tissue from the patient’s original surgery; FR-α staining does not significantly change between new diagnosis and then recurrent disease.