A personalized cancer vaccine comprised of a chimpanzee adenovirus vector (ChAdV) encoding twenty tumor-specific neoantigens (TSNAs) that have been identified through genetic sequencing of a patient's tumor cells, with potential immunostimulatory and antineoplastic activities. Upon intramuscular administration of the adenoviral-TSNA priming vaccine GRT-C901, the adenovirus infects cells and expresses the TSNAs. This stimulates the host immune system to mount a cytotoxic T-lymphocyte (CTL) response against tumor cells expressing the TSNAs, leading to tumor cell lysis. Adenoviral-TSNA vaccine GRT-C901 is followed by monthly boosting with a self-amplifying mRNA (SAM) boosting vaccine that encodes the same 20 target TSNAs. The combined immunotherapy product, consisting of priming and boosting vaccines, is referred to as GRANITE-001.