The therapy uses an AAV vector engineered to cross the blood-brain barrier via the human Transferrin Receptor 1 (hTfR1), delivering a three-hairpin artificial miRNA payload under a neuron-specific promoter to silence the MAPT gene, which encodes the tau protein implicated in these disorders. AviadoBio and Apertura Gene Therapy announced a licensing agreement for Apertura’s TfR1 CapX capsid, which has demonstrated widespread transduction of neurons and astrocytes throughout the brain and spinal cord in preclinical testing. Under the agreement, AviadoBio will leverage TfR1 CapX to drive development of its pipeline built on its proprietary vMiX RNAi platform, which enables targeted, durable gene silencing with potential for lifelong reduction of disease-causing gene expression after a single administration.
AVB-406 was developed using the vMiX platform, which enabled systematic screening of more than 1,000 potential miRNA target sites. In preclinical studies, AVB-406 was evaluated for target engagement, biodistribution, dose-responsive activity, tolerability, and efficacy in human iPSC models and mice. The therapy sustained dose-dependent MAPT mRNA knockdown in brain cortex tissue in humanized mice, including in key brain regions associated with Alzheimer's pathology, and in situ hybridization confirmed neuronal specificity of miRNA guide expression.
AVB-406 was well tolerated across all animal studies conducted to date, with no treatment-related adverse findings, including at dose levels achieving up to 80% MAPT mRNA knockdown. According to major media reports, the data demonstrate progression of AVB-406 across preclinical validation, platform discovery, and scalable manufacturing, and support the company’s plans to advance into clinical trials for Alzheimer's by the end of 2026. AviadoBio will present key data on AVB-406 at the upcoming American Society of Gene & Cell Therapy Annual Meeting.
Alzheimer’s disease and other tauopathies are progressive brain disorders characterized by abnormal changes in tau protein that disrupt communication between brain cells, leading to cognitive decline, memory loss, and changes in behavior or movement. Major media reports note that these conditions are characterized by the pathological accumulation of misfolded, aggregated tau protein encoded by the MAPT gene. AVB-406 has broader potential utility in other primary and secondary tauopathies, including frontotemporal dementia (FTD-MAPT, tau-FTD), primary progressive aphasia, corticobasal degeneration, progressive supranuclear palsy, and chronic traumatic encephalopathy.
Alex Bloom, Chief Technology Officer of AviadoBio, said there are no approved therapies that target tau as a key driver of cognitive decline in Alzheimer’s disease and other tauopathies. "The data we are presenting at ASGCT validate both the AVB-406 program and the broader potential of our vMiX platform to address the underlying drivers of neurodegenerative disease," Bloom said. AviadoBio’s pipeline also includes AVB-101, an investigational gene therapy for frontotemporal dementia with GRN mutations (FTD-GRN), currently in a Phase 1/2 clinical trial in the UK, Europe, USA, and Canada.
AVB-101 is an AAV-based gene supplementation therapy designed to deliver a functional GRN gene copy to restore progranulin levels in the brain via a one-time administration. The ASPIRE-FTD Phase I/II clinical study is evaluating AVB-101 delivered into the thalamus of FTD-GRN patients. To date, three subjects have been dosed in the ASPIRE-FTD trial, and the study is actively recruiting in Poland, Spain, the Netherlands, and the USA, with additional countries and sites planned.
Preliminary data suggest acceptable safety and tolerability of AVB-101, including the administration procedure. However, there is a discrepancy in reported recruiting countries: the trial is described as being in the UK, Europe, USA, and Canada, while active recruitment is listed in Poland, Spain, the Netherlands, and the USA. This may reflect different stages of site activation or outdated information.
AviadoBio also has an intravitreally delivered optogenetic investigational gene therapy for retinal dystrophies in clinic for retinitis pigmentosa and geographic atrophy. Frontotemporal dementia is a devastating form of early-onset dementia characterized by rapid decline in executive function, behavior, and/or language, and typically leads to death within seven to 13 years of symptom onset and three to 10 years from diagnosis. FTD has a substantially greater impact on work, family, and finances than Alzheimer's disease due to its earlier age of onset, often striking between ages 45-68.
FTD can be familial or sporadic, with around one-third of cases being familial and having a strong genetic component; the majority of hereditary FTD cases are caused by autosomal dominant mutations in three genes, including the GRN gene. S. and EU5 are living with FTD due to GRN mutations, with around 2,000 new cases confirmed annually.
Currently, there are no disease-modifying treatments available for FTD. Amyotrophic lateral sclerosis is a devastating multisystem neurodegenerative disease primarily characterized by degeneration of both upper and lower motor neurons. 5 million people worldwide, with progressive symptoms including night blindness, reduction in peripheral and central vision, and reduced ability to see details and colors.
The specific data presented at ASGCT supporting the clinical timeline have not been detailed, and the exact countries currently recruiting for the ASPIRE-FTD trial remain unclear due to conflicting reports. The timeline for AVB-406's IND filing and first-in-human dosing has not been disclosed, and potential off-target effects or long-term safety concerns of sustained MAPT knockdown in the central nervous system are unknown. How AVB-406 compares to other tau-targeting therapies in development, such as antisense oligonucleotides or antibodies, has not been addressed.