What it is
Researchers gave an individualized neoantigen mRNA vaccine to 14 patients with triple-negative breast cancer following surgery and neoadjuvant or adjuvant therapy. In nearly all patients, high-magnitude, mostly de novo T cell responses to multiple neoantigens appeared and remained functional for several years, with a large proportion of these T cells developing into two subsets: ready-to-act cytotoxic effector cells and stem cell-like memory cells. Eleven patients remained relapse-free for up to six years after vaccination. Recurrence occurred in three patients, including the individual with the weakest vaccine-induced T cell response, who then achieved complete remission on subsequent anti-PD-1 therapy.
Why it matters
Triple-negative breast cancer has few targeted options, and whether a personalized cancer vaccine can raise neoantigen-specific T cell immunity that persists rather than fading has been unclear. Here the responses stayed functional for several years across 14 patients, documenting durable vaccine-induced immunity in this setting.
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Filed undermRNA vaccine, neoantigen, triple-negative breast cancer, T cell immunity, cancer immunotherapy