A cancer vaccine consisting of self-replicating RNA (srRNA) encoding a patients tumor-specific neoantigens, with potential immunomodulatory and antineoplastic activities. Upon administration of neoantigen srRNA vaccine JCXH-212, the srRNA is taken up by and translated into the neoantigens in the patients antigen-presenting cells (APCs), primarily dendritic cells (DCs), and presented by major histocompatibility complex (MHC) molecules on the surface of the APCs. This may activate tumor antigen-specific T-cells to kill cancer cells expressing these neoantigens.