Individualized mRNA (neoantigen) vaccines

Treatment begins with sequencing DNA from the patient's resected tumor and comparing it with the DNA of their healthy cells. Computer algorithms select up to 34 neoantigens — protein fragments produced by mutations and present only in the cancer — and a strand of mRNA carrying their blueprints is synthesized for that patient alone. After injection, the patient's own cells briefly produce these fragments and display them to the immune system, which learns to recognize cells bearing the same marks: the tumor cells. In INTerpath-001, 1,137 patients received either the vaccine (up to nine doses every three weeks) together with pembrolizumab — a checkpoint inhibitor that releases the brakes on T cells — or pembrolizumab alone, for about one year. Pairing a vaccine that points the immune system at the tumor with a drug that unblocks the resulting response is the core idea of the program; the companies reported no new safety signals beyond those known from earlier studies.