
AstraZeneca has announced updated exploratory results from the TOPAZ-1 Phase III clinical trial, indicating that Imfinzi (durvalumab) plus standard-of-care chemotherapy offered long-term overall survival (OS) benefit in advanced biliary tract cancer (BTC) patients at three years.
The randomised, global, double-blind, placebo-controlled, multicentre trial was conducted across 105 centres in 17 countries and enrolled 685 adult patients.
It assessed Imfinzi plus chemotherapy, comprising gemcitabine plus cisplatin, versus a placebo plus chemotherapy as a first-line treatment.
Evaluating overall survival was the trial’s primary goal while progression-free survival, objective response rate, and safety were the key secondary endpoints.
The trial’s findings are claimed to represent the longest survival follow-up ever reported for a global, randomised Phase III trial in this setting.
After a median follow-up of 41.3 months, the Imfinzi combination regimen lowered morality risk by 26%, compared with chemotherapy alone.

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By GlobalDataThe median OS in the Imfinzi arm was 12.9 months, compared with 11.3 months in the placebo arm.
Most notably, the three-year survival rate was more than double for patients treated with the Imfinzi-based regimen.
In October 2021, the TOPAZ-1 trial met its primary endpoint of OS during an interim analysis, demonstrating a 20% decline in mortality risk following treatment with the Imfinzi regimen, versus chemotherapy alone.
Imfinzi plus chemotherapy was found to be well-tolerated, without any new safety signals reported with extended follow-up.
AstraZeneca Oncology research and development executive vice-president Susan Galbraith said: “TOPAZ-1 raised the bar for the treatment of advanced biliary tract cancer, showing a remarkable survival benefit for Imfinzi added to chemotherapy with a well-tolerated regimen.
“These data represent the longest survival follow-up reported for immunotherapy in this setting, and the three-year landmark survival improvement underscores our commitment to improving long-term outcomes in gastrointestinal cancers.”
Earlier this month, AstraZeneca reported positive results from a Phase III trial of Imfinzi in patients with small cell lung cancer.