Nouscom has closed a $135 million Series D to finance the global trial intended to support approval of NOUS-209, its off-the-shelf vaccine candidate for people with Lynch syndrome. The round moves the program toward the test that matters: whether an immune response seen in a small study translates into fewer cancers.
The published Phase 1b/2 study enrolled 45 carriers and made safety and immune response its primary endpoints. No treatment-related serious adverse events were recorded; all 37 evaluable participants developed a neoantigen-specific response, and 85% of those assessed still had a response after one year. Yet the single-arm study found no statistically significant change from baseline in the overall share of participants with adenomas or in adenoma counts, so it could not establish cancer prevention.
Lynch syndrome is caused by inherited defects in genes that repair DNA. NOUS-209 encodes 209 shared frameshift-peptide targets in two viral vectors: an initial great-ape adenovirus injection followed eight weeks later by a modified-vaccinia booster. Because the targets recur across Lynch-associated precancers and cancers, the candidate can be prepared in advance rather than customized around an individual tumor.
The practical burden today is repeated surveillance and, for some carriers, preventive surgery. The Associated Press profiled trial participant Stacy Norton, a Houston doctor whose two adult children inherited her Lynch mutation. Norton underwent yearly colonoscopies and reported that her first two after vaccination were polyp-free, her first such results since 2014. Her experience illustrates the potential benefit but does not establish efficacy.
In an October 25 ESMO update, MD Anderson investigators said two revaccination strategies administered one year after the initial series strengthened T-cell responses and produced no severe side effects. The strongest immune boost occurred in the group receiving a single neoantigen booster, and no advanced colorectal cancers were detected in follow-up colonoscopies. The update still did not provide a controlled prevention comparison.
M Ventures and Revelation Partners co-led the financing. Angelini Industries, the European Investment Bank through its Aurea facility and Neva SGR joined as new investors, while existing backers also participated. NOUS-209 received FDA Fast Track designation in June. Lead investigator Eduardo Vilar-Sanchez told the Associated Press in August that he expected a larger study to begin in early 2027, although Nouscom has not disclosed its planned enrollment or comparator.