GV1001 is a telomerase-specific, promiscuous class II peptide vaccine which is currently in an advanced stage of clinical development. This article reviews the biological rationale underpinning the design of ongoing studies with the vaccine as well as its immunogenicity and clinical activity. It places GV1001 in the context of other immunotherapeutic approaches targeting telomerase and assesses the chances of the vaccine becoming a future standard of care in the treatment of cancer.