A chimeric mouse/human monoclonal antibody with potential antineoplastic activity. Monoclonal antibody Ch14.18 binds to the ganglioside GD2 and induces antibody-dependent cell-mediated cytotoxicity and complement-dependent cytotoxicity against GD2-expressing tumor cells. GD2 is overexpressed in malignant melanoma, neuroblastoma, osteosarcoma, and small cell carcinoma of the lung.