Possibility of immunotherapy for biliary tract cancer: how do we prove efficacy? Introduction to a current ongoing phase I and randomized phase II study to evaluate the efficacy and safety of adding Wilms tumor 1 peptide vaccine to gemcitabine and cisplatin for the treatment of advanced biliary tract cancer (WT-BT trial).

BACKGROUND/PURPOSE: In biliary tract cancer, few clinical studies evaluating immunotherapy have been reported. A phase I and randomized phase II study with Wilms tumor 1 (WT1) peptide vaccine plus gemcitabine and cisplatin (GC) for chemo-naïve patients with unresectable or recurrent biliary tract cancer was started, because the overexpression of WT1 is seen in the majority of patients with this disease, encouraging the potential of WT1-based immunotherapy. This trial was registered at the UMIN Clinical Trials Registry as UMIN 000004886.

METHODS AND RESULTS

The aim of this trial is to evaluate the efficacy and safety of the regimen and to determine whether the regimen should be compared with the current standard regimen, GC, in a subsequent phase III trial for patients with unresectable or recurrent biliary tract cancer. Six patients in the phase I study and a total of 100 patients in the phase II study will be accrued over a 2-year period. The patients in the phase II study will be randomized at a 2:1 ratio to receive GC either with or without WT1 peptide vaccine. The primary endpoint of the phase II study is the 1-year overall survival rate.

CONCLUSIONS

This is the first randomized trial to evaluate the use of immunotherapy in patients with advanced biliary tract cancer.