# A randomised trial of a shared-antigen vaccine to prevent Lynch syndrome cancers

Source: https://onco.cc/ideas/idea-prev-lynch-frameshift-vaccine-rct/  
OnCo record `idea-prev-lynch-frameshift-vaccine-rct` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Lynch syndrome tumours share predictable mutations the immune system can target. A vaccine in early trials could be tested to see if it prevents polyps and cancers in carriers.

## Summary

Lynch syndrome tumours share predictable frameshift neoantigens the immune system can target, so this idea runs a randomised phase 2/3 of the Nouscom frameshift peptide vaccine Nous-209 in carriers, on a background of aspirin, with adenoma incidence at three years as the primary endpoint and colorectal cancer incidence as secondary. Nous-209 has phase 1b immunogenicity data in Lynch carriers, and carriers have high event rates that make prevention trials feasible. The test is a 600-carrier RCT. At early-clinical maturity it addresses the bottlenecks Inherited risk is mostly unidentified and Prevention we already have is not deployed, and relates to Cancer interception vaccines for high-risk carriers.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Vaccination reduces adenoma incidence in Lynch carriers by at least 30% over three years.
- Rationale: Frameshift neoantigens in mismatch-repair-deficient tumours are recurrent and immunogenic, and carriers have high event rates that make trials feasible.
- Proposed test: 600-carrier RCT.
- Maturity: early-clinical
- Actor: industry

## Sources

- Bottleneck evidence (Inherited risk is mostly unidentified): Childers et al., National estimates of genetic testing in women with breast or ovarian cancer (JCO 2017): https://doi.org/10.1200/JCO.2017.73.6314

## Connected records

- ideas: [Cancer interception vaccines for high-risk carriers](https://onco.cc/ideas/idea-interception-vaccines/)
- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Endometrial cancer](https://onco.cc/cancers/endometrial/), [Mismatch-repair deficient (MSI-high) colorectal cancer](https://onco.cc/cancers/msi-high-colorectal/)
- fronts: [Immunotherapy](https://onco.cc/fronts/immunotherapy/), [Prevention & Risk](https://onco.cc/fronts/prevention/)
- technologies: [Off-the-shelf cancer vaccines](https://onco.cc/technologies/shared-antigen-vaccine/)
- companies: [Nouscom](https://onco.cc/companies/nouscom/)
- terms: [Microsatellite instability (MSI-H) / mismatch repair deficiency (dMMR)](https://onco.cc/terms/msi/), [Neoantigen](https://onco.cc/terms/neoantigen/)
- bottlenecks: [Inherited risk is mostly unidentified](https://onco.cc/bottlenecks/b-hereditary-risk/), [Prevention we already have is not deployed](https://onco.cc/bottlenecks/b-prevention-adoption/)
- key papers: [First trial of a vaccine against the shared neoantigens of mismatch-repair-deficient cancers](https://onco.cc/key-papers/paper-lynch-frameshift-vaccine-ccr-2020/), [National Estimates of Genetic Testing in Women With a History of Breast or Ovarian Cancer](https://onco.cc/key-papers/paper-childers-j-clin-oncol/)
- roadmaps: [Cancer prevention roadmap: tobacco control and vaccines → biomarker-guided chemoprevention → interception in carriers](https://onco.cc/roadmaps/prevention-roadmap/)

---
JSON: https://onco.cc/api/v1/entities/idea-prev-lynch-frameshift-vaccine-rct.json