Survival Benefits From Durvalumab Not Affected by Antibiotic Use Among Patients With Biliary Tract Cancer
Exploratory Subgroup Analysis from TOPAZ-1
Exploratory Subgroup Analysis from TOPAZ-1
According to an exploratory subgroup analysis from the TOPAZ-1 study, there was no meaningful difference in overall survival (OS) or progression-free survival (PFS) for participants who received antibiotics during the study period compared to those who did not.
This analysis was presented on Friday, January 20, 2023, at the American Society of Clinical Oncologists Gastrointestinal Cancers Symposium in San Francisco, CA, by Aiwu Ruth He, MD, Lombardi Comprehensive Cancer Center at Georgetown University, Washington, DC.
In the double-blind, phase 3 study patients with advanced biliary tract cancer were randomized to receive either durvalumab plus gemcitabine-cisplatin (n =341) , or placebo plus gemcitabine-cisplatin (n = 344). Dr He and coauthors wrote, “Use of antibiotics during [immune checkpoint inhibitor] treatment has been correlated with poorer OS and PFS.” In this exploratory subgroup analysis, overall survival and progression-free survival was assessed by systemic antibiotic use during the study. Antibiotic use was defined as ≥1 dose 15 days before the first dose of durvalumab/placebo to 14 days after the last dose of durvalumab/placebo.
There were 49.0% of patients in the durvalumab arm who used antibiotics during the study and 48.5% in the placebo arm. In the durvalumab arm, overall survival was similar between patients who had received antibiotics (12.6 months) and those who had not (13.0 months). The median PFS of those patients who received antibiotics in the durvalumab arm was 7.3 months, compared with 7.2 months for those who did not receive antibiotics.
Dr He et al concluded, “These results support that people receiving [durvalumab] maybe treated with antibiotics when clinically indicated.”
Source:
He AR, Tan BR, Suksombooncharoen T, et al. Outcomes by antibiotic use in participants with advanced biliary tract cancer treated with durvalumab or placebo plus gemcitabine and cisplatin in the phase 3 TOPAZ-1 study. Presented at 2023 ASCO Gastrointestinal Cancers Symposium; January 19-21, 2023; San Francisco, CA. Abstract 550
