Imfinzi™ reduces risk of death in biliary tract cancer patients

Positive results from the TOPAZ-1 Phase III trial showed AstraZeneca’s Imfinzi (durvalumab), in combination with chemotherapy, demonstrated a statistically significant and clinically meaningful improvement in overall survival (OS) and progression-free survival (PFS) versus chemotherapy alone as a first-line treatment for patients with advanced biliary tract cancer (BTC).

BTC is a group of rare and aggressive cancers that occur in the bile ducts and gallbladder, with approximately 210,000 people worldwide diagnosed each year. These patients have a poor prognosis, with approximately five to 15 percent of all patients with BTC surviving five years.

“After minimal progress for more than a decade in advanced biliary tract cancer, the TOPAZ-1 results are a tremendous advance for our patients, showing a clear survival benefit for Imfinzi added to chemotherapy compared to standard of care with a remarkable safety profile,” commented Dr Do-Youn Oh, 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.

In a predefined interim analysis, of the 685 patients treated with Imfinzi in combination with standard-of-care chemotherapy, 20 percent experienced a reduction in the risk of death versus chemotherapy alone. Median OS was 12.8 months versus 11.5 for chemotherapy. An estimated 25 percent of patients were still alive at two years versus 10 percent for chemotherapy.

TOPAZ-1 (NCT03875235) results also showed a 25 percent reduction in the risk of disease progression or death with Imfinzi plus chemotherapy. Median PFS was 7.2 months for the combination versus 5.7 for chemotherapy. Patients treated with Imfinzi plus chemotherapy achieved an objective response rate (ORR) of 26.7 percent versus 18.7 percent for patients treated with chemotherapy alone.

Imfinzi plus chemotherapy did not increase the discontinuation rate due to adverse events (AEs) compared to chemotherapy alone. Grade 3 or 4 treatment-related AEs were experienced by 62.7 percent of patients treated with Imfinzi and chemotherapy, and by 64.9 percent of patients receiving chemotherapy alone. Treatment-related AEs led to discontinuation in 8.9 percent of patients treated with the Imfinzi combination versus 11.4 percent of patients receiving chemotherapy.

Susan Galbraith, Executive Vice President, Oncology R&D, AstraZeneca, added: “The results from the TOPAZ-1 trial challenge treatment expectations in advanced biliary tract cancer and provide compelling evidence that longer-term survival is possible. Overall survival improves over time with an estimated one in four patients on Imfinzi plus chemotherapy alive at two years compared to one in 10 on chemotherapy alone. This is a potential new standard of care for patients in this setting and we remain committed to making advances in gastrointestinal cancers with high unmet need.”