RAHWAY, N.J. — The U.S. Food and Drug Administration has approved pembrolizumab and pembrolizumab QLEX, in combination with paclitaxel with or without bevacizumab, for the treatment of adults with PD-L1–positive platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal carcinoma who have received one or two prior systemic therapies.
The approvals make the pembrolizumab-based regimens the first PD-1 inhibitors authorized for patients with platinum-resistant disease whose tumors express PD-L1 with a combined positive score of at least 1, as determined by an FDA-authorized test.
The decision is based on results from the Phase 3 KEYNOTE-B96 clinical trial, also known as ENGOT-ov65, which evaluated pembrolizumab plus paclitaxel, with or without bevacizumab, compared with placebo plus paclitaxel, with or without bevacizumab. Trial data showed the pembrolizumab regimen reduced the risk of disease progression or death by 28 percent and reduced the risk of death by 24 percent in patients with PD-L1–positive, platinum-resistant recurrent ovarian cancer.
Median progression-free survival for patients receiving the pembrolizumab-based regimen was 8.3 months, compared with 7.2 months for those receiving placebo. Median overall survival was 18.2 months in the pembrolizumab group versus 14.0 months in the control group.
“For many patients with ovarian cancer, the disease can become platinum-resistant, at which point recurrence is not just a setback — it’s when options can become limited, and the reality patients face can change very quickly,” said Dr. Bradley Monk, a gynecologic oncologist and medical director of the Late-Stage Clinical Research Program at Florida Cancer Specialists and Research Institute. “For patients who have been previously treated with standard platinum-based therapies, the FDA approvals of these pembrolizumab-based regimens offer the possibility of more time.”
KEYTRUDA QLEX was approved based on evidence from studies conducted with pembrolizumab, along with additional data comparing the pharmacokinetics, efficacy, and safety profiles of the two formulations.
“Historically, the prognosis has been poor for patients living with platinum-resistant recurrent ovarian cancer who have limited treatment options that may reduce the risk of disease progression or death,” said Dr. Gursel Aktan, vice president of global clinical development at Merck Research Laboratories. “Introducing the first PD-1 inhibitors for platinum-resistant ovarian cancer expands what’s possible for patients facing this disease and reinforces our commitment to advancing treatments across women’s cancers.”
In the KEYNOTE-B96 study, 643 patients were enrolled regardless of PD-L1 status, with 72 percent having tumors that expressed PD-L1. Nearly three-quarters of participants received bevacizumab during the trial, and almost half had a platinum-free interval of less than three months.
The safety profile of pembrolizumab in combination with paclitaxel, with or without bevacizumab, was consistent with known risks of immunotherapy and chemotherapy. Serious adverse reactions occurred in more than half of treated patients, and fatal adverse events were reported in a small percentage. The most commonly reported side effects included gastrointestinal symptoms, fatigue, hair loss, peripheral neuropathy, infections, endocrine abnormalities, and changes in blood counts and laboratory values. Pembrolizumab was permanently discontinued due to adverse reactions in 16 percent of patients.
The approval provides a new treatment option for patients with platinum-resistant ovarian cancer, a population with historically limited therapeutic choices and poor outcomes.
