Voyager Therapeutics, Inc.

Item 8.01 Other Events. On July 13, 2026, Voyager Therapeutics, Inc. (the “Company”) presented good laboratory practice (“GLP”) toxicology data for VY1706, the Company’s investigational tau silencing gene therapy developed to target intracellular and extracellular tau for Alzheimer’s disease (“AD”), at the Alzheimer’s Association International Conference. The three- and six-month GLP toxicology data presented demonstrated a favorable tolerability profile for VY1706 in non-human primates (“NHPs”) in the study, with no adverse clinical pathology or histopathological findings observed in the central nervous system (“CNS”), dorsal root ganglia, and peripheral organs (including liver) up to the highest dose tested of 5 x 1013 vector genomes / kilogram. The GLP data also showed a single intravenous dose of VY1706 in NHPs achieved broad, durable, and dose-dependent CNS delivery with up to 75% lowering of microtubule-associated protein tau (MAPT) mRNA and tau protein in key AD-relevant brain regions through six months. Additionally, ALPL, a well-conserved brain vasculature endothelial receptor, was shown to mediate VY1706 blood-brain barrier transport in the study, supporting the potential for cross-species translatability. As previously disclosed, the Company received U.S. Food and Drug Administration Investigational New Drug clearance for VY1706 in June 2026 and plans to begin dosing in a multi-site, open-label, dose-escalation clinical trial of VY1706 in the second half of 2026. Cautionary Note Regarding Forward-Looking Statements This Current Report on Form 8-K contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995 and other federal securities laws, including, without limitation, implied and express statements about the Company’s beliefs and expectations regarding the Company’s advancement of the VY1706 program, including the timing and achievement of clinical development milestones such as the Company’s intention to initiate clinical trials, clinical trial enrollment, and achievement of first-in-human dosing in AD in the second half of 2026 and the therapeutic potential, safety, and pharmacological effect of VY1706. The use of words such as “may,” “will,” “might,” “would,” “could,” “should,” “expect,” “plan,” “anticipate,” “believe,” “potential,” “intend,” “seek,” “predict,” “estimate,” “project,” “target,” or “continue” and other similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. All forward-looking statements are based on management’s current estimates and assumptions and are subject to a number of risks, uncertainties, and important factors that may cause actual results to differ materially from any forward-looking statements in this Form 8-K. Factors include, among others, the risks and uncertainties inherent in the development of product candidates, including the initiation, enrollment, timing, cost, progress, and results of the Company’s planned and future clinical trials; expectations and decisions of regulatory authorities; the Company’s ability to replicate positive results from earlier preclinical studies or clinical trials in current or future clinical trials; potential adverse events the Company may encounter that could negatively impact development; outcomes of third-party preclinical studies and clinical trials that could impact the Company’s development plans; the Company’s ability to demonstrate that current or future product candidates are safe and effective for their proposed indications; the Company’s scientific approach and continued development of its technology platforms, including the TRACER and non-viral discovery platforms; the development by third parties of capsid or non-viral identification platforms that may be competitive to its platforms and programs; the Company’s ability to create and protect its intellectual property rights; the progress and success of programs under current or future collaboration and license agreements; the sufficiency of the Company’s cash resources to fund its operations and pursue its corporate objectives; and technical and other unexpected hurdles in the development, manufacture and supply of the Company’s product candidates, may delay its timing, change its plans, increase its costs, or otherwise negatively impact its business or the sufficiency of its cash resources to fund operations. These risks and uncertainties are described in the Company’s most recent Annual Report on Form 10-K filed with the Securities and Exchange Commission as updated by its subsequent filings with the Securities and Exchange Commission. All information in this Form 8-K is as of today’s date, and any forward-looking statement speaks only as of the date on which it was made. The Company undertakes no obligation to publicly update or revise this information or any forward-looking statement, whether as a result of new information, future events or otherwise, except as required by law.