CHIMERIC MOLECULES AND METHODS OF USE
Chimeric molecules comprising endostatin and all or a portion of an Ig (Ig) molecule are used to treat tumors. A chimeric molecule, including endostatin fused to an Ig domain of an anti-HER2/neu antibody exhibited longer serum half-life and stability than native endostatin. <SUP>125</SUP>I-labeled anti HER2/neu IgG3-endostatin chimeric molecule and anti-HER2/neu IgG3-endostatin was 6 fold faster than that of anti-HER2/neu IgG3 (CLss=0.374 and 0.062ml/min/kg, respectively), however, the specific tumor radiolocalization indices of anti-HER2/neu IgG3-endostatin were greater than those of anti-HER2/neu IgG3. Anti-HER2/neu IgG3-endostatin inhibited tumor growth more effectively than endostatin alone, anti-HER2/neu IgG3 antibody, or the combination of antibody and endostatin.