Imfinzi plus chemotherapy further improved overall survival benefit in advanced biliary tract cancer in the TOPAZ-1 phase III trial, reducing the risk of death by 24% in additional follow-up

These results from TOPAZ-1, the first Phase III trial to show improved OS with an immunotherapy combination in this setting, will be presented at the European Society for Medical Oncology (ESMO) Congress 2022 in Paris (abstract #56P).

The updated results for Imfinzi plus chemotherapy (gemcitabine plus cisplatin) showed enhanced clinical efficacy after an additional 6.5 months of follow-up, demonstrating a 24% reduction in the risk of death versus chemotherapy alone (based on a hazard ratio [HR] of 0.76; 95% confidence interval [CI], 0.64–0.91). Updated median OS was 12.9 months versus 11.3 with chemotherapy. More than two times as many patients were estimated to be alive at two years versus chemotherapy alone (23.6% versus 11.5%). Results were seen across all prespecified subgroups, regardless of disease status, tumour location or PD-L1 expression. In addition, OS benefit was observed in patients whose tumours stayed the same size (stable disease) as well as in patients whose tumours got smaller or disappeared (responders).

The safety profile of Imfinzi plus chemotherapy continued to be well-tolerated, with no new safety signals observed with longer follow-up. Grade 3 or 4 treatment-related AEs were experienced by 60.9% of patients treated with Imfinzi and chemotherapy, and by 63.5% of patients receiving chemotherapy alone. Imfinzi plus chemotherapy did not increase the discontinuation rate due to adverse events (AEs) compared to chemotherapy alone (8.9% for the Imfinzi combination versus 11.4% for chemotherapy).

Do-Youn Oh, MD, PhD, Professor, Division of Medical Oncology, Department of Internal Medicine at Seoul National University Hospital and Seoul National University College of Medicine, and principal investigator in the TOPAZ-1 Phase III trial, said: “It's exciting to see the improved overall survival delivered by durvalumab plus chemotherapy over the current standard of care for patients with advanced biliary tract cancer after a median follow-up of nearly two years. With limited treatment advances over the past decade, these patients have long faced a dismal prognosis. For the first time, an immunotherapy-based combination has shown the ability to alter the course of treatment for this disease and should become the new standard of care.”

The FDA approved durvalumab (Imfinzi) in combination with gemcitabine and cisplatin for adult patients with locally advanced or metastatic biliary tract cancer on 2 September 2022.