Pembrolizumab Plus Chemotherapy Significantly Improves Overall Survival in First-Line Advanced, Unresectable Biliary Tract Cancer

Positive results from the phase 3 KEYNOTE-966 trial have found that pembrolizumab (Keytruda, Merck) in combination with standard of care chemotherapy demonstrated a statistically significant and clinically meaningful improvement in overall survival (OS) in the first-line treatment of patients with advanced or unresectable biliary tract cancer.

KEYNOTE-966 is a randomized, double-blind phase 3 trial evaluating pembrolizumab in combination with gemcitabine and cisplatin compared to placebo plus gemcitabine and cisplatin for the first-line treatment of advanced and/or unresectable biliary tract cancer. The primary endpoint was OS and secondary endpoints included progression-free survival, objective response rate, duration of response, and safety.

The trial enrolled 1069 patients who were randomized to receive pembrolizumab 200 mg every 3 weeks for up to approximately 2 years plus gemcitabine and cisplatin, or the placebo plus chemotherapy arm.

“Biliary tract cancer is typically diagnosed at an advanced stage, and these patients face a poor prognosis, with 5-year survival rates estimated to be approximately 5% to 15%,” said Eliav Barr, MD, senior vice president, head of global clinical development, and chief medical officer at Merck Research Laboratories, in a press release. “We are very encouraged by these overall survival results that show the potential benefit of Keytruda in addition to chemotherapy for biliary cancer patients who are in urgent need of new treatment options.”

Biliary tract cancer encompasses several rare and highly aggressive cancers in the gallbladder and bile ducts. It is the second most common type of primary liver cancer after hepatocellular carcinoma, accounting for 15% of all liver cancers. An estimated 211,000 new cases of biliary tract cancer are diagnosed annually, and 174,000 patients die from the disease globally each year.

Biliary tract cancer is most commonly diagnosed in patients between 50 and 70 years of age, and 70% of these patients are diagnosed at an advanced stage. Patients diagnosed with biliary tract cancer face a very poor prognosis, with an estimated 5-year survival rate between 5% and 15%, according to researchers.

The safety profile in the KEYNOTE-966 trial was consistent with that observed in previously reported studies. Specific data and results will be presented at an upcoming medical meeting and will be submitted to regulatory authorities.

Pembrolizumab is an anti-programmed death receptor-1 (PD-1) therapy that increases the ability of the body’s immune system to help detect and fight tumor cells. It is a humanized monoclonal antibody that blocks the interaction between PD-1 and PD-L2, thereby activating T lymphocytes which can affect both tumor cells and healthy cells. Pembrolizumab is continuing to be investigated for gastrointestinal cancer indications, including gastric, hepatobiliary, esophageal, pancreatic, and colorectal cancers.

REFERENCE

Merck’s Keytruda (pembrolizumab) Plus Chemotherapy Significantly Improved Overall Survival Versus Chemotherapy in First-Line Advanced or Unresectable Biliary Tract Cancer in KEYNOTE-966 Trial. News release. Merck; January 25, 2023. Accessed January 25, 2023. https://www.merck.com/news/mercks-keytruda-pembrolizumab-plus-chemotherapy-significantly-improved-overall-survival-versus-chemotherapy-in-first-line-advanced-or-unresectable-biliary-tract-cancer-in-keynote-966/