Angeles Alvarez Secord, MD, a gynecologic oncologist at Duke Health, shared encouraging new data Sept. 15 on ovarian cancer treatment at the European Society for Medical Oncology meeting in Barcelona, Spain.
She was principal investigator of the PICCOLO trial which tested mirvetuximab soravtansine (MIRV) for a particularly challenging form of cancer known as platinum-sensitive ovarian cancer (PSOC). The study focused on patients with high levels of a protein called folate receptor alpha (FRα).
The results were promising: over half of the patients in the Phase II trial saw their cancer shrink or disappear, with an overall response rate of 51.9%. The treatment’s effects lasted an average of 8.25 months and patients went about seven months without their cancer worsening.
MIRV was approved by the U.S. Food and Drug Administration in 2023 for the treatment of platinum-resistant ovarian cancer (PROC). The drug is currently undergoing evaluation for approval in Europe, potentially expanding access to patients globally.
“Platinum-based chemotherapy can become less effective over time, and patients may experience severe side effects,” said Secord, a professor of obstetrics and gynecology in the division of gynecologic oncology at Duke University School of Medicine. “MIRV offers a potentially more effective and less toxic treatment option.”
Secord highlighted a major challenge faced by patients: those who take PARP inhibitors (PARPi), a type of maintenance treatment used after chemotherapy to keep cancer from coming back, tend to respond less to future treatments. This is especially true for therapies that use platinum-based drugs.
MIRV, however, has shown promise even in this difficult-to-treat population, providing a much-needed option for patients with few effective alternatives left.
Response rates were over 70% for those patients who have a BRCA gene mutation that increases the risk of breast cancer and ovarian cancer, or had not received a prior PARPi. For patients whose cancer worsened after taking PARP inhibitors, the treatment still showed positive results, with a 45.8% response rate. On average, the benefits lasted more than seven months.
The PICCOLO trial also tested how safe and effective MIRV is for patients and found that most patients handled the drug well. Common side effects included neurosensory issues, gastrointestinal problems, dry eye, and blurred vision, but trial data indicated that these were mostly mild and resolved over time.
MIRV is an antibody-drug conjugate (ADC) that combines an antibody that targets cancer cells with a potent anti-cancer drug. It is the first FDA-approved ADC for ovarian cancer and the only new therapy specifically for PROC.
The unique composition of MIRV is considered key to its effectiveness. The drug is designed to target FRα, a protein commonly found on the surface of ovarian cancer cells. Once attached, a cleavable linker releases a potent cancer-killing agent, DM4, which interferes with the cancer cells’ ability to divide and spread.
This targeted approach allows MIRV to zero in on cancer cells while sparing healthy ones, offering a strategic advantage over traditional chemotherapies that can affect both.
About 20,000 women in the United States will receive a new diagnosis of ovarian cancer this year, according to the American Cancer Society. Diagnoses have been slowly falling over the past few decades. Fewer women are dying of ovarian cancer as well, likely due to better treatments and fewer women being diagnosed.
The global study screened 302 patients who had undergone at least two rounds of chemotherapy, and 79 eligible participants were enrolled in the clinical trial.
At the meeting, Secord, a member of the Duke Cancer Institute, thanked those patients, their families, clinical investigators, and research teams from the United States and abroad who participated in the trial.
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