In vivo VEGF capture leads to compartment-specific reduction of leukemia load exclusively in the CNS. Leukemia load in CNS (A), BM (B), and spleen (C) of mice xenografted with 3 CNS⁺ primografts X1, X1_1 (replicate), X2, and X24 comparing control (ctrl)- and bevacizumab (beva)-treated recipients showing CNS compartment–specific leukemia reduction on VEGF capture (significantly lower CNS tumor load in X1, X1_1, and X2; trend toward lower CNS leukemia load in X24). X1: n = 4 for untreated, n = 5 for beva-treated; X1_1: n = 5 per group; X2: n = 5 for untreated, n = 3 for beva-treated; X24: n = 5 per group (bars indicate median values; significance by 2-tailed Mann-Whitney U test; P values as indicated in graphs). (D) Reduced meningeal ALL infiltration in post-treatment MRI analysis (transversal and coronal sections; meninges highlighted by dotted lines in 1 hemisphere) after bevacizumab compared with ctrl treatment. (E) Reduced meningeal infiltration of huCD19⁺ BCP ALL cells (immunohistochemistry staining for huCD19, BZ-9000; size as indicated).