RNA Vaccine Achieves Objective Responses in End-Stage Melanoma

RNA vaccines against COVID-19 and other viral infections have generated excitement. They can be produced rapidly, and they elicit both antibody and T-cell responses: mRNA (typically enclosed in lipid nanocapsules) is injected and taken up by host dendritic cells, which then produce mRNA-encoded peptides (immunogens) in conjunction with major histocompatibility complex I proteins — necessary for a robust T-cell response.

A German team created an RNA vaccine that produces four tumor-associated antigens prevalent in melanoma; they immunized 89 patients with late-stage melanoma who had been treated with checkpoint-inhibitor (CPI) drugs. Echoing prior experience in mice, repeated infusions of the vaccine elicited robust expansion of CD4+ and CD8+…