Vaccine targeting a common brain tumor mutation: 66% of phase 1 participants were alive eight years later
Vaccine targeting a common brain tumor mutation: 66% of phase 1 participants were alive eight years later
In the NOA16 trial, 33 patients with IDH1-mutant astrocytomas received a peptide vaccine alongside surgery, radiotherapy, and chemotherapy. In the final analysis at eight years, 66% of participants were alive, and 42% had experienced no tumor progression.
An astrocytoma is a tumor that arises from the brain's supporting cells. Some of these tumors carry the same alteration in the isocitrate dehydrogenase-1 gene: IDH1 R132H. It occurs early and remains present in the descendants of the original tumor cell. This is usually a major constraint for personalized cancer vaccines. Finding a mutation is not enough. Researchers must also show that the cell presents a fragment of the altered protein on HLA, the molecule that displays antigens to T-cells. IDH1 R132H gives the immune system an altered protein shared by many tumor cells.
IDH1-vac is a short fragment of this protein. Patients received it after standard treatment to train their T-cells to recognize mutant IDH1 specifically. In the team's first publication in 2021, 93.3% of participants developed this immune response. Vaccine-related adverse events did not exceed grade 1 severity.
In an article published on July 1, 2026, Nature Cancer reported the final follow-up of the same group. Among patients with grade IV astrocytoma, median overall survival reached 106.1 months. This is substantially longer than the range of 31.6–56.4 months reported in the older published cohorts used by the authors for comparison. Participants with a durable antibody response were more likely to have a favorable disease course. In an inflamed lesion that could initially appear to represent tumor growth, the researchers found vaccine-induced T-cells.
The figure of 66% applies only to this group. All 33 patients underwent surgery, radiotherapy, and chemotherapy. A single group of 33 people cannot separate the contribution of IDH1-vac from the effects of tumor grade, the extent of surgery, and the patients' own characteristics. A durable immune response may have been more common among patients whose tumors already had more favorable biology.
A randomized phase 2 trial should compare patients receiving the same standard treatment with or without IDH1-vac. That comparison will show whether an immune response to the shared mutation adds years to survival.