First evidence for the antitumor activity of nanoliposomal irinotecan with 5-fluorouracil and folinic acid in metastatic biliary tract cancer

BACKGROUND: Therapeutic options are limited for advanced, metastatic biliary tract cancer. The pivotal NAPOLI-1 trial demonstrated the superior clinical benefit of nanoliposomal irinotecan (Nal-IRI) in gemcitabine-pretreated patients with metastatic pancreatic ductal adenocarcinoma; however, the antitumor activity of Nal-IRI in biliary tract cancer is unknown. This is the first report describing the efficacy of Nal-IRI in biliary tract cancer. METHODS: In this multicenter retrospective cohort analysis, we identified patients with metastatic biliary tract adenocarcinoma who were treated with Nal-IRI in combination with 5-fluorouracil and folinic acid following tumor progression under standard therapy at one of the study centers between May 2016 and January 2019. We assessed disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). RESULTS: There were 14 patients; the median age at the time of diagnosis and the median age at the initiation of Nal-IRI were 59.3 and 60.0 years, respectively. Nal-IRI in combination with 5-fluorouracil and folinic acid was administered as second-, third-, fourth-, and fifth-line treatment in 6 (43%), 5 (36%), 2 (14%), and 1 (7%) patient with metastatic disease, respectively. The objective DCR with Nal-IRI was 50% (7/14 patients). Six patients (43%) had partial response, and one patient (7%) had stable disease. Progressive disease was observed in seven patients. The median PFS and median OS following Nal-IRI initiation were 10.6 and 24.1 months, respectively. CONCLUSIONS: This retrospective analysis provides the first evidence that Nal-IRI might exhibit a clinical meaningful antitumor activity in metastatic biliary tract cancer.