Lynch syndrome vaccine shows immune response in early trial

An early-phase trial of the Nous-209 vaccine in people with Lynch syndrome reported the shot was safe and produced immune responses in all 45 participants, and investigators observed fewer advanced precancerous colon lesions among those with strong responses; larger randomized trials are needed to test whether the vaccine prevents cancer.

An early-phase trial tested Nous-209, a vaccine designed to train the immune system to recognise proteins that appear on precancerous cells in people with Lynch syndrome. The study enrolled 45 participants and reported the vaccine was safe and produced measurable immune responses. Investigators noted fewer advanced precancerous colon lesions among participants who mounted a strong immune response. Researchers say larger randomized trials are necessary to determine whether the vaccine actually prevents cancer. Key facts: - The Nous-209 trial enrolled 45 people with Lynch syndrome and its results were published in Nature Medicine. - The vaccine, developed with an inactivated adenovirus, was reported as safe and elicited immune responses in all participants, with varying strength. - Colonoscopies one year after vaccination showed fewer advanced precancerous lesions among participants with stronger immune responses. - The study was an early-phase safety and immune-response trial; a larger randomized controlled trial is required to test efficacy. Summary: The trial's early findings show a vaccine can generate targeted immune responses in people with Lynch syndrome and that stronger responses were associated with fewer advanced precancerous colon lesions. Whether Nous-209 prevents cancer remains undetermined at this time and depends on the outcomes of larger randomized trials.