In vivo effects of veltuzumab compared with rituximab and after NK/neutrophil depletion in Raji lymphoma model. (A) Comparison of therapeutic effects on survival of RPCI-SCID mice bearing Raji lymphoma cells treated with 10 mg/kg veltuzumab or rituximab (or untreated control) on days 5, 10, 15, and 20 after tumor inoculation intravenously (N = 15 per group), indicating significantly improved survival (P = .005) of the veltuzumab group compared with the rituximab group. (B) The effect of depleting NK cells and neutrophils on anti-lymphoma activity in SCID mice. Veltuzumab therapy consisted of 200 μg given intravenously on days 3, 5, 7, and 11; control mice received 100 μL saline. Depletion of NK cells and neutrophils abrogated the anti-lymphoma activity of veltuzumab.