Effect of G6-23-IgG or mFlt(1-3)-IgG on postnatal body growth, organ weight, and survival of neonatal mice. (A) Ten C57BL/6 neonatal mice per group were treated for 10 days with either compound at a dose of 25 mg/kg intraperitoneally. Body weights were assessed daily. Data represent mean ± standard deviation. (B) Kaplan-Meier survival curves of C57BL/6 neonatal mice treated with either mFlt(1-3)-IgG, G6-23-IgG, or an isotype-matched control antibody. Both compounds induced a similar increase in death. (C) Percent body and organ weights from anti-VEGF–treated C57BL6 neonatal mice relative to controls on treatment day 5. Each group consisted of 5 specimens, representing mean ± standard deviation. Data are from 1 representative of 2 independent experiments. (D) Changes in hematologic parameters in neonatal mice aged 5 days treated with anti-VEGF [G6-23-IgG, mFlt(1-3)-IgG] or a vehicle control (phosphate-buffered saline; PBS). Whole blood was collected at necropsy and analyzed by automated hematologic analysis of white blood cell count (WBC), neutrophil count (NEU), lymphocyte count (LYM), eosinophil count (EOS), basophil count (BAS), red blood cell count (RBC), hemoglobin level (HGB), hematocrit (HCT), and platelet count (PLT). Data represent mean ± SD.