Antitumor activity of anti-human PD-1 antibody pembrolizumab analog (in-house) in non-small cell lung cancer cell line NCI-H1975 CDX model established with huHSC-B-NDG hIL15, FcγR KO mice. Human CD34+ HSCs (3×10⁴) were intravenously engrafted into B-NDG hIL15, FcγR KO mice within 4-12 hours after being irradiated with 0.9 Gy of X-ray. NCI-H1975 cells (5E6) were subcutaneously inoculated into B-NDG hIL15, FcγR KO mice when the frequency of hCD45+ cells in blood was more than 25%. Mice were grouped when the tumor volume reached approximately 80-100 mm³, at which time they were treated intraperitoneally with pembrolizumab analog with dose and schedule indicated in panel (female, 15-week-old, n=8/9). The results showed that pembrolizumab analog could effectively inhibit tumor growth in lung cancer CDX model established with huHSC-B-NDG hIL15, FcγR KO mice. Values are expressed as mean ± SEM.