nCage Therapeutics is developing synthetic viral-like particles as vaccine candidates. The company uses de novo-designed viral particles to mount multiple antigens, allowing an increased immune response versus soluble protein. nCage's platform is based on the bacterial TRAP protein, using cross-linking to build a spherical protein cage structure from TRAP rings. Cross-linking chemistry can be changed, which allows for a programmable opening and closing of the TRAP cage. nCage has developed universal external and internal hooks that allow for mounting protein antigens on the exterior of the TRAP cage and loading internal cargo (which can be additional protein or peptide antigens). nCage's programmable opening and closing of their synthetic VLP platform distinguishes other VLP technology in development. nCage has been able to demonstrate an increased B and T cell response to currently accepted vaccine technologies in animal models, including challenge models.