We have developed a precision biologics platform, termed Immuno-STAT (IST), which recapitulates elements of the antigen-specific and co-stimulatory signals experienced at the immunological synapse and is in multiple clinical trials. MHC covalently linked to antigenic peptide and co-stimulatory modules (MOD) allows for the targeted activation of disease-relevant T cells while leaving the remaining T cell repertoire untouched, thus minimizing off-target effects associated with global immunotherapies. The modularity of the platform is a central feature, as replacement of the peptide allows for new disease indications to be targeted, and substitution of the MOD allows for new mechanisms to be explored. We seek to rapidly produce personalized IST cocktails that fully leverage a patient’s unique neoantigen repertoire. Currently, each new peptide-MHC combination demands re-initiation of CMC and cGMP processes, often requiring 12 months for recombinant production. To overcome this limitation, we are producing empty ISTs, engineered constructs that maintain structural integrity in the absence of peptide. These empty ISTs will serve as off-the-shelf, universal, peptide-accepting scaffolds for the rapid, site-specific coupling of synthetic peptides, including post-translationally modified neoantigens. This approach decouples IST production from full recombinant manufacturing, shifting the rate-limiting step to peptide synthesis, which can be completed in a clinically relevant time frame.