Tislelizumab differs from other PD-1 inhibitors by having an engineered Fc region that abolishes antibody-dependent cellular phagocytosis (a potential resistance mechanism to anti-PD-1 therapy), which may promote a high ORR and durable tumor responses.19–21 The PFS observed in ZSAB-TOP was numerically comparable to those in the KEYNOTE-966 and TOPAZ-1 trials, potentially due to complexities involved in assessing PFS in patients with BTC. Here, PDCD1 is linked to neoplasm.