A phase I trial of B7-transfected or parental lethally irradiated allogeneic melanoma cell lines to induce cell-mediated immunity against tumor-associated antigen presented by HLA-A2 or HLA-A1 in patients with stage IV melanoma. NCI protocol T93-0161. BRMP protocol 9401.

T cell lines generated by primary in vitro stimulation with B7-expressing HLA-A2+ melanoma cells lyse HLA-A2+ melanomas, but not non-melanomas that are HLA-A2+. Other data have demonstrated lack of response of these T cell lines against non-HLA-A2 melanomas. These concepts are verified by data from MALME MEL, which is killed, and MALME FIB, which is not. In no case was lysis directed at targets expressing potential allo-antigens (except for HLA-A2+ melanomas). A19 and Aw33 have not been excluded as possible allo-targets (but no data suggests they are). In total, it appears that much of the lytic activity observed in the two T cell lines is directed against HLA-A2-restricted, melanoma-specific antigens.