How should immunotherapy be incorporated into the treatment strategy for patients with resectable stage III microsatellite instability–high (MSI-H) or mismatch-repair-deficient (dMMR) extrahepatic cholangiocarcinoma?

Great question, and one that we do not have clear data to support, but could certainly extrapolate. KEYNOTE 158 trial included 22 patients with advanced cholangiocarcinoma, and response was 40.9% with a median duration of response not reached (mOS 24.3 months; 6.5-NR) (Marabelle et al., PMID 31682550). There are case reports and series that also showed high response, some even with complete response. We looked at 22 MSI-H BTC across two institutions treated with immunotherapy with or without che...