Our vision for a new type of cancer treatment is based on an implantable therapeutic system capable of ‘programmable’ on-demand delivery of drugs directly to the tumor. We conceive an implantable iontronic switch (bioSWITCH) to enable a spatiotemporally controlled administration of highly potent chemotherapeutics, without the need for systemic administration of (pro)drugs or drug conjugates. This radically new technology will be realized by a combination of next-level tools. As a result, bioSWITCH can generate previously unobtainable discrete as well as continuous drug concentration profiles at the tumor site, and thus allows for the use of highly potent drugs that are otherwise not applicable due to high cytotoxicity. The goal is to demonstrate the technology’s potential to effectively interfere with tumor progression using a xenograft pancreas cancer mouse model. Efficiently shrinking tumors in size allows for surgical resection of previously non-operable tumors and dramatically increases survival rates. Our consortium of world leading academics and pioneering SMEs will ensure the translation of this disruptive technology into the market to maximize the socioeconomic impact.