Posted: Friday, September 30, 2022
According to Amit Mahipal, MBBS, MPH, of the Mayo Clinic, Rochester, Minnesota, and colleagues, there are limited data regarding the role of immunotherapy in the treatment continuum of advanced biliary tract cancer. A multisite, single-institution study, which was published in JCO Precision Oncology, evaluated the efficacy and safety of immune checkpoint inhibitor monotherapy in a cohort of patients with this disease.
“Immune checkpoint inhibitors are well tolerated and have modest antitumor activity in patients with advanced biliary tract cancers,” the investigators remarked. “The study result supports the exploration of tumor mutational burden as a potential predictive biomarker for response to immune checkpoint inhibitors in patients with advanced biliary tract cancer.”
Using an institutional database, the investigators identified 47 patients with advanced biliary tract cancers who received at least one dose of a PD-1 or PD-L1 immune checkpoint inhibitor. PD-1 blockers included pembrolizumab, nivolumab, and toripalimab; PD-L1 blockers included atezolizumab and durvalumab. Approximately 50% of patients had received pembrolizumab. A majority of patients (78.7%) had intrahepatic cholangiocarcinoma, 17% had gallbladder carcinoma, and 4% had hilar cholangiocarcinoma.
The overall response and disease control rates were 10.6% and 53.2%, respectively. The median duration of progression-free survival was 3.6 months, and the median duration of overall survival was 6.9 months.
Based on a biomarker analysis, patients with a tumor mutational burden of more than five mutations per megabase experienced a prolonged median duration of progression-free survival (6.4 vs. 2.2 months; P = .0027). Although the investigators reported no unexpected adverse events, 68.1% of patients reported fatigue, 34% reported nausea, and 21.3% reported diarrhea. One patient had a fatal event of pneumonitis, and grade 4 myositis was observed in one other patient.
Disclosure: For full disclosures of the study authors, visit ascopubs.org.