Nouscom Highlights Potential of NOUS-209 to Intercept Cancer in Lynch Syndrome Carriers in Seminal Nature Medicine Publication

January 16, 2026 |

8 min read

Lynch Syndrome (LS) is a common hereditary condition that significantly increases the lifetime risk of developing multiple cancers
NOUS-209 is an off-the-shelf cancer immunotherapy designed to induce T cells against neoantigens present in tumors and precancer lesions in LS carriers
Publication in Nature Medicine underscores significance of NOUS-209 clinical data and its innovative approach to intercept cancer before it develops
Data support advancing NOUS-209 into FDA- and EMA-aligned registration-enabling clinical trial for cancer interception in LS carriers

BASEL, Switzerland – January 16, 2026 – Nouscom, a clinical-stage biotech company developing next-generation immunotherapies to treat cancer at all stages, from early cancer interception to late-stage metastatic disease, today announced that results from its Phase 1b/2 clinical trial of NOUS-209 in Lynch Syndrome (LS) carriers have been published in Nature Medicine (D’Alise et al). Publication of the results in a leading high-impact medical journal marks a key milestone for Nouscom and advances the emerging field of cancer interception, reinforcing the potential of NOUS-209 to transform preventive care for LS carriers.

NOUS-209 is an off-the-shelf cancer immunotherapy designed to induce T cells against neoantigens present in tumors and precancer lesions with Microsatellite instability (MSI). It leverages Nouscom’s proprietary viral vector platform to deliver 209 shared frameshift peptide (FSP) neoantigens found in MSI tumors, training the immune system to recognize and eliminate precancerous and cancerous cells. LS is the most common hereditary cancer syndrome, significantly increasing the lifetime risk of multiple cancers. For example, LS carriers face up to an 80% risk of colorectal cancer, along with elevated risks for endometrial, urothelial, ovarian and other cancers. For LS carriers - who currently rely on intensive screening or elective organ-removal surgery - the prospect of an immune-driven preventive option represents a significant paradigm shift.

“These findings highlight the strong potential of NOUS-209 as a cancer interception strategy for individuals with Lynch Syndrome,” said the study’s principal investigator, Eduardo Vilar-Sanchez, M.D., Ph.D., Professor of Clinical Cancer Prevention at The University of Texas MD Anderson Cancer Center. “The data shows that NOUS-209-induced T cells persist, effectively target and kill MSI tumor cells, and support long-term immune protection. The absence of advanced adenomas post-treatment is particularly encouraging.”

“NOUS-209’s ability to safely induce broad, potent, and durable immune responses against shared neoantigens is unique,” said Elisa Scarselli, M.D., Chief Scientific Officer of Nouscom. “These data reinforce our confidence in NOUS-209’s potential to intercept cancer before it develops in high-risk individuals with Lynch Syndrome.”

Key Findings:

Favorable Safety Profile: NOUS-209 was well tolerated, with no serious treatment-related adverse events.
Potent and Durable Immunogenicity Profile: All evaluable participants developed robust, durable T cell responses against a wide array of neoantigens, with annual retreatment effectively boosting the response.
Functional Anti-Cancer Activity: Induced T cells demonstrated direct tumor cell killing capability ex vivo and exhibited the desired effector memory phenotype, supporting long-term immune surveillance.
Clinical Evidence of Efficacy: Reduced frequency of MSI precancer lesions and no new advanced adenomas were detected one year post-treatment, providing clinical evidence of cancer interception in LS carriers.

Marina Udier, Ph.D., CEO of Nouscom concluded, “The publication of NOUS-209 data in Nature Medicine is a pivotal moment—not just for Nouscom, but for the future of cancer prevention. For individuals with Lynch Syndrome, there is now the promise of an immunotherapy that can train the immune system to stop cancer before it takes hold. This is more than a scientific milestone; it is a potentially transformative approach for Lynch Syndrome carriers as they deserve a better way to manage their cancer risk. We are committed to advancing NOUS-209 into a registration-enabling clinical trial to help transform lives and redefine the role of immunotherapy in oncology.”

The clinical trial NCT05078866 was supported by the National Cancer Institute of the National Institutes of Health under Award Number UG1CA242609 (project director Dr. Eduardo Vilar-Sanchez). The trial was conducted through the iCAN-PREVENT consortium at MD Anderson, with support from the Data Management, Auditing, and Coordination Center (grant U24CA242637).

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Reference

D’Alise, AM. et al. Nous-209 neoantigen vaccine for cancer prevention in Lynch Syndrome carriers: a phase 1b/2 trial. Nature Medicine (2026); DOI: 10.1038/s41591-025-04182-9.

About NOUS-209
NOUS-209 is an investigational off-the-shelf cancer immunotherapy that targets tumors with mismatch repair deficiency (dMMR) and microsatellite instability (MSI). These tumors produce unique markers known as frameshift peptide (FSP) neoantigens, which are unique to cancerous cells and absent in healthy cells. NOUS-209 is comprised of two proprietary viral vectors able to deliver 209 shared FSP neoantigens and train the immune system to recognize and attack cancerous and precancerous cells before tumors can develop.

Phase 1b/2 data demonstrated the safety of NOUS-209 and its ability to stimulate potent immune responses in LS carriers¹^,2, supporting its advancement into a registration-enabling Phase 2/3 trial in cancer interception. It also demonstrated clinical activity including objective responses and strong disease control in combination with pembrolizumab in a difficult-to-treat patient population of advanced dMMR and/or MSI-H metastatic CRC (mCRC) patients refractory to anti-PD-1 therapy³. NOUS-209 is also being studied in a randomized Phase 2 study in combination with pembrolizumab for the first line treatment of advanced dMMR and/or MSI-H mCRC. Data from the successfully completed Phase 1b trial were published in Science Translational Medicine⁴.

About Lynch Syndrome
Lynch Syndrome (LS) is a common inherited condition that significantly increases a person’s risk of developing cancer over their lifetime, especially colorectal cancer (CRC) (up to 50% risk, compared to 2% for general population), endometrial cancer (up to 50% risk, compared to 1-2% for general population) and urothelial cancer (up to 25% risk, compared to 1-2% for general population)^5,6,7^,8. LS also elevates the risk of developing other cancers including gastric, ovarian, prostate and pancreatic. LS is caused by inherited mutations in specific genes responsible for repairing DNA, leading to the buildup of harmful genetic errors that can accumulate, triggering development of tumors. Currently, managing LS is limited to frequent screenings - such as colonoscopy to catch cancer early, but shown not to reduce cancer incidence⁹ – and elective surgery, which is invasive, expensive, and negatively impacts quality of life. As a pioneering approach to cancer interception, Nouscom’s investigational immunotherapy, NOUS-209, is designed to train the immune system to recognize and stop cancer before it develops.

About Cancer Interception
Cancer interception is an innovative approach that aims to stop cancer in its earliest stages before tumors fully develop and spread. Unlike traditional therapies that target established cancers, interception strategies harness advancements in immuno-oncology that can train the immune system to recognize and eliminate precancerous and cancerous cells. This approach is particularly crucial for those with high-risk genetic conditions such as LS who are predisposed to developing MSI-associated cancers.

About Nouscom
Nouscom is a clinical-stage biotech company pioneering next-generation neoantigen-targeted immunotherapies to treat cancer at all stages, from early cancer interception to late-stage metastatic disease. Its proprietary viral vector platform enables broad and durable immune activation by delivering optimized neoantigens that train the immune system to recognize and fight cancer. Nouscom’s lead program, NOUS-209, is an off-the-shelf immunotherapy in advanced clinical development for cancer interception in LS and the treatment of MSImCRC. The company’s clinical stage portfolio also includes NOUS-PEV, a personalized neoantigen immunotherapy, with published data from a successfully completed Phase 1b trial¹⁰. Nouscom’s current investors include 5AM Ventures, Andera Partners, Angelini Ventures, Bpifrance, EQT Life Sciences, Indaco Venture Partners SGR, M Ventures, Panakes Partners, Revelation Partners, Versant Ventures and XGEN Ventures.
For more information on Nouscom, please visit the company’s website at www.nouscom.com or follow us on LinkedIn.

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