Figure 1.

Experimental timeline for evaluation of pembrolizumab for CU-ACC2-M2B PDX tissue in hu-CB-BRGS mice. Newborn BRGS mice were irradiated with 300 rad before injection of CB CD34⁺ human hematopoietic stem cells. Following confirmation of human chimerism in the blood at 10, 15, and 19 weeks, mice were randomized into equivalent groups based on chimerism and implanted with CU-ACC2 PDX tissue that had been developed and passaged in a nude mouse. Once tumors reached 150 to 300 mm³, pembrolizumab treatments were begun. Mice were euthanized when tumor volumes approximated 2000 mm³, tumors and lymph organs were excised, and immune parameters were evaluated by flow cytometry and immunohistochemistry.