Phase I study of bintrafusp alfa, a bifunctional fusion protein targeting TGF-β and PD-L1, in patients with pretreated biliary tract cancer

Background Patients with biliary tract cancer (BTC) have poor prognosis with few treatment options. Bintrafusp alfa, a first-in-class bifunctional fusion protein composed of the extracellular domain of the transforming growth factor (TGF)-βRII receptor (a TGF-β ‘trap’) fused to a human IgG1 antibody blocking programmed death ligand 1 (PD-L1), has shown clinical efficacy in multiple solid tumors. Methods In this phase I, open-label trial...