Synergistic effect of ALM and RTX in vivo. Animals were inoculated with primary leukemic cells from patient 24 (top) or patient 15 (bottom). Starting from the time points indicated by the arrows, animals received 250 μg ALM plus 250 μg RTX (A + R) or saline daily for 5 days per week for a total of 3 weeks. For each case, 2 independent experiments were performed with 3 treated animals and 3 control animals per group. Data are mean ±SD of all measurements. (A) Leukemic cell counts in peripheral blood (PB) during treatment, and leukemic cell content of PB, spleen (SP), and bone marrow (BM) at the experimental endpoint. Treatment start is indicated by arrows. (B) Flow cytometric analysis of bone marrow of ALM + RTX–treated and control treated animals. Cells were stained with antimurine CD45 (muCD45) and antihuman CD45 (HuCD45). The elliptic gate indicates the location of leukemic cells.