Posted: Thursday, November 2, 2023
On October 31, 2023, the U.S. Food and Drug Administration (FDA) approved the use of the PD-1 inhibitor pembrolizumab in combination with gemcitabine plus cisplatin for locally advanced unresectable or metastatic biliary tract cancer. The approval was based on results from the phase III KEYNOTE-966 trial, in which the triplet regimen demonstrated a statistically significant improvement in the study’s primary endpoint of overall survival, reducing the risk of disease progression or death by 14% compared with chemotherapy alone.
The multicenter KEYNOTE-966 trial enrolled 1,069 patients with locally advanced unresectable or metastatic biliary tract cancer who had not received prior systemic therapy for advanced disease. Patients were randomly assigned (1:1) to receive either pembrolizumab on day 1 plus gemcitabine and cisplatin on days 1 and 8 every 3 weeks or placebo on day 1 plus gemcitabine and cisplatin on the previous schedule. Cisplatin was administered for a maximum of eight cycles; gemcitabine was continued at the physician’s discretion.
Pembrolizumab plus chemotherapy demonstrated a statistically significant improvement in overall survival compared with placebo plus chemotherapy, with a hazard ratio of 0.83 (95% confidence interval [CI] = 0.72–0.95; one-sided P value = .0034). The median overall survival was 12.7 months (95% CI = 11.5–13.6 months) and 10.9 months (95% CI = 9.9–11.6 months) in the respective arms.
Adverse reactions leading to the interruption of pembrolizumab occurred in 55% of patients. The most common adverse reactions or laboratory abnormalities (≥ 2%) leading to interruption of therapy were decreased neutrophil count, decreased platelet count, anemia, decreased white blood cell count, pyrexia, fatigue, cholangitis, increased alanine transaminase, increased aspartate transaminase, and biliary obstruction.
The recommended pembrolizumab dose is 200 mg every 3 weeks or 400 mg every 6 weeks until disease progression or unacceptable toxicity. Pembrolizumab should be administered prior to chemotherapy when given on the same day.
For more information, see the prescribing information.