Voyager Therapeutics, Inc. (Nasdaq: VYGR) presented six-month toxicology data for its investigational gene therapy VY1706, targeting tau protein in Alzheimer's disease, at the Alzheimer's Association International Conference in London on July 13, 2026.

The data, drawn from a good laboratory practice study in non-human primates, showed that a single intravenous dose of VY1706 was well tolerated, with no adverse clinical pathology or histopathological findings in the central nervous system, dorsal root ganglia, or peripheral organs, including the liver, at the highest dose tested of 5E13 vg/kg.

VY1706 achieved up to 75% reduction in MAPT mRNA and tau protein in Alzheimer's disease-relevant brain regions over six months following a single IV dose, with the effect described as broad, durable, and dose-dependent.

The therapy uses a vectorized siRNA encapsulated in Voyager's TRACER AAV capsid, which crosses the blood-brain barrier by leveraging ALPL, a brain vasculature endothelial receptor. Voyager states the receptor is well-conserved across species, which the company says supports potential cross-species translatability.

The U.S. Food and Drug Administration cleared an Investigational New Drug application for VY1706 in June 2026. Voyager said it expects to begin dosing adults with early Alzheimer's disease in the second half of 2026.

"The data we are presenting at AAIC continue to reinforce the compelling pharmacology and safety profile and durability we have observed to date with VY1706, which is the first tau-targeted gene therapy with an IND cleared by the FDA," said Alfred W. Sandrock, Jr., M.D., Ph.D., Chief Executive Officer of Voyager.

Three-month GLP toxicology data for VY1706 were previously presented at the American Society of Gene & Cell Therapy's 2026 Annual Meeting in May.