Cancer immunotherapy and adoptive transfer of genetically manipulated T cells in particular has shown promising results for the treatment of cancer. Central in cancer immunotherapy is the activation of tumour-specific T cells. However, the wide-spread clinical use of T cell therapies remains limited due to costly, time-consuming and labour-intensive processes associated with the ex vivo activation and expansion of tumour-specific T cells. Artificial antigen presenting cells (aAPCs) have been developed as an alternative for efficient activation of T cells. In the ERC project ‘PATHFINDER’, Prof. Figdor and his team have developed aAPCs or synthetic dendritic cells (sDCs) based on highly flexible polyisocianide (PIC) polymers, that mimic naturally occurring DCs. The semi-flexible polymer backbone allows for proper arrangement and clustering of antigen and (co-)stimulatory markers, resulting in potent activation and expansion of T cells. With the use of PIC based sDCs, we propose a production platform for tumour specific T cells suitable for cancer immunotherapy. In this ERC PoC project, a team of technological and commercial experts will investigate commercial feasibility of this innovative approach.