Among patients evaluable for response (n = 17), the confirmed ORR was 47% (n = 8; 95% confidence interval [CI]: 23, 72), the disease control rate was 65% (n = 11; 95% CI: 38, 86) and the median duration of response was 6.6 months (95% CI: 3.2, not estimable)....Zanidatamab is well tolerated with promising and durable anti-tumor activity in patients with HER2 overexpressing BTC.