ERBB2 and neoplasm: Next, we evaluated the therapeutic efficacy of IBI315 in vivo using Her2‐positive humanized tumor xenograft mouse models established as reported previously.[16] Humanized mice bearing N87 tumors (n = 30) or Her2‐positive PDX (Figure 2F, PDX‐1; n = 35) were randomly divided into five treatment groups, and IBI315, IgG (control), trastuzumab, sintilimab or combined trastuzumab and sintilimab were injected intraperitoneally.