3F8 is a murine IgG3 monoclonal antibody specific for the antigen disialoganglioside GD2- Immimofluorescence staining showed strong binding of 3F8 to 15 of 17 human osteosarcomas, including primary and metastatic tumors. The targeting potentials of the native monoclonal antibody (3F8) and the F(ab')2 fragment (p-3F8) were tested in BALB/c athymic nude mice xenografted with human osteosarcomas. After radio-labeling with iodine using the chloramine T method, both 3F8 and p-3F8 retained immunoreactivities. The irrelevant IgG3 antibody TIBI14 and its F(ab')2 fragment were used as negative controls. A Ewing's sarcoma xenograft, which was low in gd2 antigen, was also studied for comparison. Mice were sacrificed 1 day and 4 days after i.v. antibody injection. 3F8 and p-3F8 showed preferential accumulation in osteosarcoma over normal tissues with tumonnontumor ratios of 2.7-58:1 and 1.4-82:1, respectively, on Day 1. These ratios improved to 10-163:1 and 6.0-75:1 on Day 4. The intact antibody 3F8 showed selective tumor uptake with a much higher percentage of iqjected dose per g than the fragment p-3F8 and exhibited a longer tissue half-life than p-3F8. These data indicate that anti-GD2 monoclonal antibodies may be useful for imaging and targeted therapy of human osteogenic sarcoma. The F(ab')2 fragment has the advantage of achieving favorable tumonnontumor ratios sooner after antibody injection while the intact antibody shows better retention by tumor tissues.
|Original language||English (US)|
|Number of pages||6|
|State||Published - 1987|
All Science Journal Classification (ASJC) codes
- Cancer Research