Durvalumab Improves Survival in Advanced Biliary Tract Cancer

Durvalumab (Imfinzi; AstraZeneca) was found to significantly improve overall survival (OS) compared with placebo plus chemotherapy in patients with advanced biliary tract cancer, according to results from the TOPAZ-1 phase 3 trial published in the New England Journal of Medicine (NCT03875235).¹ Further, the drug produced improvements in prespecified secondary end points such as progression-free survival (PFS) and objective response rate (ORR) compared with placebo plus chemotherapy.

“The combination of durvalumab and chemotherapy is a significant advance for patients after more than a decade of limited progress, and this regimen should become a new standard of care option once approved,” TOPAZ-1 lead investigator Juan W. Valle, MD, professor of Medical Oncology at the University of Manchester, said in a press release.²

The double-blind, placebo-controlled study randomized 685 patients with previously untreated unresectable or metastatic biliary tract cancer or with recurrent disease 1:1 to receive durvalumab (n=341) or placebo (n=344) in combination with gemcitabine plus cisplatin for up to 8 cycles, followed by durvalumab or placebo monotherapy until disease progression or unacceptable toxicity. The primary objective was to assess OS, with secondary end points that included PFS, ORR, and safety.

At the data cutoff, 198 patients (58.1%) in the durvalumab cohort had died compared with 226 patients (65.7%) in the placebo cohort. The hazard ratio for OS was 0.80 (95% confidence interval [CI], 0.66 to 0.97; P=0.021) and the estimated 24-month OS rate was 24.9% (95% CI, 17.9 to 32.5) in the durvalumab cohort compared with 10.4% (95% CI, 4.7 to 18.8) in the placebo group.

The hazard ratio for PFS was 0.75 (95% CI, 0.63 to 0.89; P=0.001). ORR was 26.7% in the durvalumab cohort vs 18.7% with placebo. Incidences of grade 3 or 4 adverse events were 75.7% and 77.8% in the durvalumab and placebo cohorts, respectively.

Updated results from TOPAZ-1 after an additional 6.5 months of follow-up found a 24% decrease in the risk of death compared with chemotherapy alone (HR 0.76; 95% CI, 0.64-0.91), with more than twice as many patients estimated to still be alive at 2 years compared with chemotherapy alone (23.6% versus 11.5%).² Updated median OS was 12.9 months in the durvalumab cohort compared with 11.3 in the chemotherapy cohort.

In September 2022, the FDA granted durvalumab and chemotherapy approval in the United States for individuals with locally advanced or metastatic biliary tract cancer based on results from the TOPAZ-1 trial. It is under review in Europe, Japan, and several other countries.

References

1. Do-Youn Oh, M.D. et al. Durvalumab plus gemcitabine and cisplatin in advanced biliary tract cancer, NEJM Evidence. June 1, 2022. Available at: https://evidence.nejm.org/doi/full/10.1056/EVIDoa2200015. Accessed December 12, 2022.

2. Imfinzi plus chemotherapy recommended for approval in the EU by CHMP as first immunotherapy regimen for advanced biliary tract cancer. AstraZeneca. News release. November 14, 2022. Accessed December 12, 2022. https://www.astrazeneca.com/media-centre/press-releases/2022/imfinzi-plus-chemotherapy-recommended-for-approval-in-the-eu-by-chmp-as-first-immunotherapy-regimen-for-advanced-biliary-tract-cancer.html#