Patients with advanced biliary tract cancer have a poor prognosis, and first-line standard of care (gemcitabine plus cisplatin) has remained unchanged for more than 10 years. The TOPAZ-1 trial evaluated durvalumab plus chemotherapy for patients with advanced biliary tract cancer.

In this double-blind, placebo-controlled, phase 3 study, we randomly assigned patients with previously untreated unresectable or metastatic biliary tract cancer or with recurrent disease 1:1 to receive durvalumab or placebo in combination with gemcitabine plus cisplatin for up to eight cycles, followed by durvalumab or placebo monotherapy until disease progression or unacceptable toxicity. The primary objective was to assess overall survival. Secondary end points included progression-free survival, objective response rate, and safety.

Overall, 685 patients were randomly assigned to durvalumab (n5341) or placebo (n5344) with chemotherapy. As of data cutoff, 198 patients (58.1%) in the durvalumab group and 226 patients (65.7%) in the placebo group had died. The hazard ratio for over- all survival was 0.80 (95% confidence interval [CI], 0.66 to 0.97; P50.021). The esti- mated 24-month overall survival rate was 24.9% (95% CI, 17.9 to 32.5) for durvalumab and 10.4% (95% CI, 4.7 to 18.8) for placebo. The hazard ratio for progression-free sur- vival was 0.75 (95% CI, 0.63 to 0.89; P50.001). Objective response rates were 26.7% with durvalumab and 18.7% with placebo. The incidences of grade 3 or 4 adverse events were 75.7% and 77.8% with durvalumab and placebo, respectively.

Durvalumab plus chemotherapy significantly improved overall survival versus placebo plus chemotherapy and showed improvements versus placebo plus chemo- therapy in prespecified secondary end points including progression-free survival and objective response rate. The safety profiles of the two treatment groups were similar. (Funded by AstraZeneca; ClinicalTrials.gov number, NCT03875235.)