Trastuzumab Deruxtecan for HER2-Positive Biliary Cancer?

Biliary cancers frequently harbor targetable mutations and gene amplified pathways, including IDH-1, FGFR2, BRAF V600E, and human epidermal growth factor receptor 2 (HER2). There is increasing evidence that a range of HER2-targeted therapies are active in HER2-positive biliary cancer.

Investigators in Japan report the results of an industry-sponsored, single-arm, phase 2 trial of the antibody–drug conjugate trastuzumab deruxtecan (T-DXd) in HER2-expressing advanced biliary cancer. Central pathologic confirmation of HER2 status by both immunohistochemistry and in situ hybridization was performed in archival tissue from 296 patients, of whom 61 (20.6%) tested HER2+. Thirty eligible patients were treated with T-DXd (5.4 mg/kg every 3 weeks), in…