Recombinant vaccinia/fowlpox NY-ESO-1 vaccines induce both humoral and cellular NY-ESO-1-specific immune responses in cancer patients

NY-ESO-1 is a cancer/testis antigen expressed in a range of human malignancies, and a number of vaccine strategies targeting NY-ESO-1 are being developed. In the present study, the safety and immunogenicity of recombinant vaccinia-NY-ESO-1 and recombinant fowlpox-NY-ESO-1 were analyzed in a series of 36 patients with a range of different tumor types. Each construct was first tested individually at two different dose levels and then in a prime-boost setting with recombinant vaccinia-NY-ESO-1 followed by recombinant fowlpox-NY-ESO-1. The vaccines were well tolerated either individually or together. NY-ESO-1-specific antibody responses and/or specific CD8 and CD4 T cell responses directed against a broad range of NY-ESO-1 epitopes were induced by a course of at least four vaccinations at monthly intervals in a high proportion of patients. CD8 T cell clones derived from five vaccinated patients were shown to lyse NY-ESO-1-expressing melanoma target cells. In several patients with melanoma, there was a strong impression that the natural course of the disease was favorably influenced by vaccination.