A phase 1b/2 study tested the neoantigen vaccine Nous-209 for cancer prevention in Lynch syndrome carriers. The vaccine uses commercially available gorilla adenovirus vectors and modified Ankara vaccinia vectors. It contains more than 200 mutated peptides present in individuals with Lynch syndrome. Lynch syndrome is associated with insufficient cellular repair of DNA pairing. The vaccine targets T-cells specific for these neoantigens. The study was published in Nature Medicine on January 16, 2026.