JCR Pharmaceuticals Highlights Preclinical CNS Gene Therapy Data for JUST-AAV Platform at ASGCT 2026

JCR Pharmaceuticals presented new preclinical findings at the American Society of Gene and Cell Therapy (ASGCT) 29th Annual Meeting demonstrating the potential of its investigational JUST-AAV platform to improve delivery of gene therapies to the central nervous system (CNS) while reducing liver exposure, a persistent challenge in adeno-associated virus (AAV)-based therapies.¹

The company showcased oral and poster presentations focused on CNS-targeting AAV capsids and blood-brain barrier (BBB)-penetrating approaches for rare neurodegenerative diseases, including GM1 gangliosidosis and neuronal ceroid lipofuscinosis (CLN1 and CLN2).¹

How does JUST-AAV aim to improve CNS gene delivery?

JUST-AAV is JCR’s proprietary AAV vector platform engineered to enhance delivery to specific tissues, including the brain and muscle, while minimizing liver tropism.¹ The technology incorporates modified capsids and transferrin receptor (TfR)-targeting strategies intended to facilitate transport across the BBB.

According to JCR, the platform is designed to address limitations associated with conventional AAV9 vectors, particularly off-target liver accumulation and insufficient CNS penetration.¹

“The presented preclinical results demonstrate that JCR’s novel capsid platform is able to deliver therapeutic agents to the central nervous system more efficiently than conventional AAV9, while reducing liver accumulation,” said Hiroyuki Sonoda, PhD, president and chief scientific officer of JCR Pharmaceuticals, in a company statement.¹

What did the GM1 gangliosidosis data show?

One ASGCT presentation described an investigational AAV9 gene therapy encoding a TfR-targeted β-galactosidase enzyme for GM1 gangliosidosis.¹ Researchers used a BBB-penetrable enzyme construct designed to enable receptor-mediated transport into the CNS.

In mouse models, intravenous administration resulted in robust hepatic expression, high circulating enzyme levels, reduced GM1 ganglioside accumulation in the brain, improved neurological function, and prolonged survival.¹ Researchers also reported comparable CNS penetration and therapeutic efficacy using a human TfR-targeted construct in a humanized disease model.¹

The findings provide translational support for potential first-in-human studies, according to investigators.¹

Could JUST-AAV expand treatment options for neurodegenerative disorders?

Additional poster data evaluated JUST-AAV-mediated therapies in CLN1 and CLN2 mouse models.¹ Investigators reported that animals treated with JUST-AAV constructs demonstrated significantly prolonged survival, preserved locomotor function, reduced neuroinflammation, and improved retinal integrity compared with disease controls and conventional AAV9 approaches.¹

Post-mortem analyses confirmed elevated therapeutic enzyme activity in brain tissue, supporting evidence of CNS delivery.¹

Separately, Alexion, AstraZeneca Rare Disease presented collaborative preclinical data involving a TfR-targeted JUST-AAV capsid engineered to reduce liver exposure while increasing brain-to-liver biodistribution ratios relative to AAV9.¹ Researchers reported dose-dependent transgene expression and favorable tolerability in mouse and non-human primate studies.¹

The broader gene therapy field continues to explore approaches that improve BBB penetration and reduce systemic toxicities associated with high-dose AAV administration.^2,3 Several CNS-targeted AAV strategies are currently under investigation in rare neurologic diseases.⁴

While the presented findings remain preclinical, the data suggest targeted AAV engineering strategies may help expand the therapeutic potential of gene therapies for CNS disorders.

References

1. JCR Pharmaceuticals presents preclinical gene therapy data that demonstrate promising central nervous system uptake at the American Society of Gene and Cell Therapy (ASGCT) 29th Annual Meeting. (2026 May 15). Business Wire. https://www.businesswire.com/news/home/20260518596351/en/JCR-Pharmaceuticals-Presents-Preclinical-Gene-Therapy-Data-that-Demonstrate-Promising-Central-Nervous-System-Uptake-at-the-American-Society-of-Gene-and-Cell-Therapy-ASGCT-29th-Annual-Meeting
2. Hudry E, Vandenberghe LH. (2019 Mar 6). Therapeutic AAV gene transfer to the nervous system: a clinical reality. Neuron. https://pubmed.ncbi.nlm.nih.gov/30844402/
3. Hordeaux J, Wang Q, Katz N, et al. The neurotropic properties of AAV-PHP.B are limited to C57BL/6J mice. (2018 Mar 7). Molecular Therapy. https://pubmed.ncbi.nlm.nih.gov/29428298/
4. Gene therapy studies for central nervous system disorders. Clinicaltrials.gov. Accessed May 19, 2026. https://clinicaltrials.gov/search?term=AAV%20central%20nervous%20system