Peg-Arg I plus Ara-C inhibit the accumulation of T-ALL cell in vivo. (A) Peg-Arg I/Ara-C homogeneously prevents the spleen growth induced by CCRF-CEM cells. Tumor size was tested after 30 days of tumor injection. (B) Survival of CCRF-CEM-bearing mice was established after therapies with PBS (Control; n = 11), peg-Arg I (n = 12), Ara-C (n = 13), or peg-Arg I/Ara-C (n = 13). (C-D) Percentage of human CD5⁺ cells was established in spleens and peripheral blood after 30 days of tumor injection in mice treated with peg-Arg I/Ara-C (n = 10) or PBS (n = 10).