LynchVax: progress toward a preventive vaccine for people with Lynch syndrome

There's encouraging news from the Oxford team working on LynchVax, a research programme exploring whether a vaccine could help prevent cancers linked to Lynch syndrome. Since late 2024 the group has been listening to our community’s hopes and questions, and sharing regular updates as the science moves toward first-in-human studies. The message is careful but hopeful: progress is real, and patient voices are shaping what comes next.

What the science is showing

Using samples generously donated by people with Lynch syndrome—alongside data from the 100,000 Genomes Project—the researchers have identified DNA changes that appear before cancer develops in Lynch-associated tissues. Because these alterations are seen across several cancer types (bowel, womb, ovary and stomach), they look like strong targets for a future vaccine that could potentially protect against multiple cancers at once. That potential still needs to be proven in trials, but it’s a major scientific step.

Progress in Oxford

On the lab side, the team has now collected over half of the planned samples from bowel precancers, as well as from bowel and womb cancers. Scientists are analysing these to find features present in Lynch-associated lesions, not in healthy tissue, that could be turned into vaccine targets. Oxford has also secured a broader £50m Cancer Immuno-Prevention Programme (with a separate industry sponsor). While not directly funding LynchVax, this infrastructure should help speed delivery of all Oxford-led cancer vaccine projects, including this one.

What’s happening elsewhere

Oxford isn’t alone. A Swiss company, Nouscom, recently reported early-phase results of its NOUS-209 vaccine in 45 people with Lynch syndrome in the US. The study wasn’t designed to prove cancer prevention, but the vaccine was well tolerated (no serious side effects reported) and generated a robust immune response, though frequent boosters may be needed. So why keep multiple efforts going? Timing (we shouldn’t pause while waiting years for outcomes), different scientific approaches (so we can tailor options to people’s genes), and improved designs that could make boosting easier.

What to expect next

The road to any preventive vaccine runs through careful regulation. Before a trial starts, agencies such as the MHRA review safety data. A Phase I study (often 6–12 months) focuses on safety in a small group; Phase II (around a year) looks for signs the vaccine is working; Phase III (several years, potentially ~1,000 people) confirms safety and effectiveness at scale. Oxford’s team plans a design similar to established vaccines, aiming for strong protection with fewer side effects, but there are no guarantees until trials are complete.

A note on placebos and trial design

Many people asked whether a prevention trial would require a placebo. The team explains that placebo groups, and keeping participants unaware of which they receive, are essential to produce reliable results. Knowing you had the vaccine can change behaviour and side-effect reporting, which can obscure the true effect. As plans move toward larger studies, the researchers are committed to co-designing trials with people who have Lynch, to address practical and ethical concerns.

At Lynch Syndrome UK, we’ll keep sharing updates as this work evolves. For now: prevention research is moving steadily, community input is front and centre, and multiple vaccine approaches are advancing in parallel, bringing us closer to answers.

If you missed this year's Lynch Syndrome UK Conference watch the recording of Dr David Church, LynchVax Project Lead, talking about the vaccine on our YouTube channel.

If you'd like to receive updates and opportunities to get involved directly, sign up to receive the LynchVax quarterly newsletter by emailing Sara Danielli: sara.danielli@medsci.ox.ac.uk, or find out more on the LynchVax website: LynchVax — Oxford Cancer

Sources: LynchVax Newsletters 1 & 2.