New Vaccines Aim to Halt Lynch-Related Colon Cancer Before Tumors Form

Lynch syndrome, an inherited defect in DNA-repair genes, raises colorectal cancer risk to as high as 80 percent. To move beyond frequent colonoscopies, scientists are creating vaccines that alert the immune system to the mutant proteins that appear in early lesions. In a first-step trial, 45 carriers, among them Dr. Stacy Norton, received a Nouscom vaccine that targets 209 such proteins, prompting a surge in tumor-killing T cells and resulting in fewer polyps after a year.

The study, reported in Nature Medicine, also included a booster dose for a subset of participants, with more data expected later this fall. Parallel efforts include an mRNA-based vaccine from Moderna being tested at Oxford University and a larger placebo-controlled trial of ImmunityBio’s Tri-Ad5 platform in California. Lead investigator Dr. Vilar-Sanchez anticipates a broader trial to begin early next year, offering hope that future carriers may reduce or eliminate the need for annual colonoscopies.