Figure 3

GBR 401 can deplete B cells in xenografted SCID mice. A/ SCID mice were irradiated, reconstituted with human PBMCs and treated with mAbs. Depletion of human B cells was monitored 4 days after antibody treatment by quantifying the proportion of total human B cells in the spleen. The graph shows pooled data from two independent studies. HER isotype control was dosed at 10 mg/kg and 2 mg/kg. B/ Patient derived CLL (n = 5) (15×10⁶) were injected i.p. in SCID mice simultaneously with purified NK cells from healthy donors (effectors/target ratio of 6) and mAb treatment (2 mg/kg). The mice were sacrificed seven days later and cell death was analyzed on peritoneal CLL cells (CD45 + CD5 + CD3-). The graph shows the absolute alive B-CLL cell number found in the peritoneal cavity. C/ Groups of 6 SCID mice were injected i.v. with 2 × 10⁵ Raji cells (day 0). Mice were treated with mAbs (GBR 401, HER, 2 mg/kg) or PBS alone at day three, seven and ten, and monitored daily and sacrificed when hind leg paralysis or signs of illness appeared. All control groups died within 24 days after Raji injection while GBR 401 increased median survival by 2.1 fold (P < .01).