Preparation and characterization of a polyvalent human melanoma antigen vaccine.

A polyvalent melanoma tumor antigen vaccine was prepared from antigens shed by a pool of human melanoma cells cultured in serum-free medium. The vaccine contained multiple melanoma associated antigens (MAAs) and was free of detectable fetal calf serum (FCS) proteins and Dr antigens. Three batches of vaccine prepared several months apart contained the same spectrum of tumor antigens. Thirteen patients with metastatic malignant melanomas were immunized intradermally with escalating doses of the vaccine in a Phase I study. There was no toxicity other than transient urticaria at the injection site. Humoral immunity, assayed by indirect immunoprecipitation, was augmented in five (38%) patients. Cellular immunity, assayed by delayed-type cutaneous hypersensitivity, was induced in four (31%) patients. Skin tests to a control vaccine prepared from pooled allogeneic lymphocytes were negative. Cutaneous metastases regressed completely in one patient who is now disease free after 2 years, and multiple cutaneous metastases have remained stable for 14 months in another patient. These results indicate that active immunization to a partially characterized polyvalent melanoma antigen vaccine is safe and can increase immunity to melanoma in some patients.