Fab-SAg treatment of humanized SCID mice carrying B-lymphoma cells reduces tumor growth. SCID mice (7 animals per group) were injected IP with 3 × 105 Daudi B-lymphoma cells. Five days later, mice were injected IP with 3 × 105 normal human peripheral blood mononuclear cells. On days 5 to 8, mice were treated with daily intravenous injections (100 μg per injection) of anti-CD19-Fab-SEAm. Control animals received saline (PBS) or C215-Fab-SEAm control fusion protein, which does not bind to B-lymphoma cells. At day 40, the animals were killed and the (▪) number of tumors and (▧) total tumor weight (mg) were determined IP. Statistical evaluation was performed using the Mann-Whitney U test, where fusion protein–treated animals were compared with PBS-treated animals (**P < .01, *P < .05). One of 2 experiments producing similar results is shown as the mean ± SEM.
