AstraZeneca (AZ) has shared positive three-year results from a late-stage study of its immunotherapy Imfinzi (durvalumab) in patients with advanced biliary tract cancer (BTC).
The phase 3 TOPAZ-1 trial has been evaluating Imfinzi in combination with chemotherapy (gemcitabine plus cisplatin) as a first-line treatment for adults with unresectable, locally advanced or metastatic BTC, including intrahepatic and extrahepatic cholangiocarcinoma, and gallbladder cancer.
Approximately 210,000 people worldwide are diagnosed each year with BTC, a group of rare and aggressive gastrointestinal cancers that form in the cells of the bile ducts, gallbladder or ampulla of Vater (where the bile duct and pancreatic duct connect to the small intestine).
TOPAZ-1 previously met its primary endpoint of overall survival in 2021, with Imfinzi plus chemotherapy shown to reduce the risk of death by 20% versus chemotherapy alone.
Susan Galbraith, executive vice president, oncology research and development, AZ, said: “TOPAZ-1 raised the bar for the treatment of advanced BTC, showing a remarkable survival benefit for Imfinzi added to chemotherapy with a well-tolerated regimen.”
According to exploratory results from the trial, which represent the longest survival follow-up reported for immunotherapy in this setting, the Imfinzi combination reduced the risk of death by 26% versus chemotherapy plus placebo at a median follow-up of 41.3 months.
The median overall was 12.9 months for the Imfinzi combination versus 11.3 months for chemotherapy alone, and more than twice as many patients on the Imfinzi-based regimen were alive at three years versus the chemotherapy/placebo cohort.
Do-Youn Oh, principal investigator in the trial, of Seoul National University Hospital and Seoul National University College of Medicine, said: “The latest data from TOPAZ-1 shows that twice as many patients with advanced BTC were still alive at three years with Imfinzi and chemotherapy, an especially meaningful advance in a setting where historically the prognosis has been poor.
“These results reinforce the long-term benefit of this immunotherapy-based combination as a standard of care for patients with this devastating disease.”
Imfinzi is already approved in a number of countries, including the UK and US, for use in combination with chemotherapy to treat locally advanced or metastatic BTC.