ANTIMELANOMA EFFECTS OF R24, A MONOCLONAL-ANTIBODY AGAINST GD(3) GANGLIOSIDE

R24, a mouse monodonal antibody against GD(3) ganglioside, is potent a t mediating in vitro effector functions such as human complement-media ted cytotoxicity and antibody-dependent cellular cytotoxicity, and can block melanoma tumor growth in animal models. Because of these proper ties and the fact that GD(3) is abundantly expressed on virtually all melanomas but is found on few normal tissues, R24 has been tested in a series of clinical trials in patients with metastatic melanoma. As a single agent, R24 can induce responses in patients treated with metast atic melanoma. Overall, there have been 10 responders out of 103 patie nts reported; two responses have been complete responses, Responses ha ve largely occurred in patients treated with intermediate doses of R24 and have included complete responses. Combining R24 with either cytot oxic drugs or cytokines has not increased this response rate, although one trial with R24 and interleukin-2 resulted in a 43% response rate and merits further investigation, Local-regional treatments R24 (intra tumor injections, regional limb perfusion, intrathecal administration) have also been attempted in a small number of patients and responses have been described. Taken together, multiple centers have reported re sponses in patients with metastatic melanoma treated with R24.