Abstract: In most cases, cancer chemotherapy and immunotherapy fail to yield durable responses, and complete and permanent regression of established tumors are rare. Here the inventors show that so-called caloric restriction mimetics (CRMs), which are natural or synthetic compounds that pharmacologically mimic the effects of fasting or caloric restriction, can be used to enhance the probability of cancer cure. The administration of several chemically distinct CRMs (such as hydroxycitrate, lipoic acid and the natural polyamine spermidine) led to the complete regression and the induction of protective anticancer immune responses in mouse models. This effect was achieved when CRMs were combined with chemotherapy and immunotherapy targeting the immune checkpoint molecules CTLA-4 and/or PD-1. Hence, caloric restriction and CRMs can be used to sensitize cancers to chemo-immunotherapy.