Active specific immunotherapy in malignant melanoma.

We have recently initiated clinical trials of active specific immunotherapy evaluating a new polyvalent melanoma cell vaccine in patients with high-risk and/or recurrent melanoma. The vaccine has been administered alone, or in combination with low-dose cyclophosphamide, as an immunomodulator of suppressor cells. Cyclophosphamide is effective in lowering suppressor cell activity in some patients undergoing active specific immunotherapy. This is not associated with an enhanced humoral immune response to melanoma-associated antigens, nor is the clinical course of those patients receiving cyclophosphamide favorably influenced. We are hopeful that other immunomodulators, alone or in combination with lower doses of cyclophosphamide, may be effective in some patients, particularly in those patients whose suppressor cell activity remains high. The optimization of the vaccine and the use of immunomodulators will enhance humoral and cellular immune responses to antigens in the allogenic vaccine that cross react with those present in the autologous melanoma, which should more favorably influence the prognosis of melanoma patients.