A multicenter, non-randomized, Phase 2 study to assess the efficacy, safety, and pharmacokinetics of trastuzumab emtansine in participants with HER2 overexpressing solid tumors including CCA where other treatment options have been exhausted (NCT02999672) was terminated early when five of seven patients with advanced pancreatic/CCA developed progressive disease. This evidence concerns the gene ERBB2 and cholangiocarcinoma.