JCR Pharmaceuticals' JUST-AAV Platform Achieves 52-Fold Improvement in Muscle Gene Delivery While Reducing Liver Exposure
核心洞察
JCR Pharmaceuticals (搜索) presented data at ESGCT demonstrating their JUST-AAV (搜索) platform achieved 28- and 52-fold higher transduction efficiencies in quadriceps and heart compared to conventional AAV9 (搜索) vectors.
The engineered capsids showed dramatically reduced liver (搜索) transduction by 160-fold compared to AAV9 (搜索), addressing a major safety concern in gene therapy delivery.
The platform successfully developed dual-targeting vectors that can deliver therapeutic agents to both brain and muscle (搜索) tissues simultaneously using combined targeting binders.
JCR Pharmaceuticals (搜索) has demonstrated significant advances in adeno-associated virus (AAV) gene therapy delivery with its proprietary JUST-AAV (搜索) capsid engineering platform, achieving dramatic improvements in targeting efficiency while reducing off-target effects. Data presented at the European Society of Gene and Cell Therapy (ESGCT) 32nd Annual Congress in Seville, Spain, showed the platform's ability to enhance delivery to the central nervous system (搜索) and muscle (搜索) tissues while minimizing liver (搜索) exposure.
Enhanced Muscle Targeting with Reduced Liver Toxicity
The JUST-AAV (搜索) platform demonstrated remarkable improvements in tissue-specific delivery compared to conventional AAV9 (搜索) vectors. In preclinical studies conducted in mice, the muscle (搜索)-targeting JUST-AAV achieved 28-fold higher transduction efficiency in quadriceps and 52-fold higher efficiency in heart tissue compared to AAV9. Simultaneously, the engineered vector showed dramatically reduced liver (搜索) transduction by 160-fold compared to AAV9, addressing a critical safety concern in gene therapy applications.
Dr. Shunsuke Iizuka, Associate Senior Scientist at JCR Pharmaceuticals (搜索), reported that the team identified a novel peptide that, when incorporated onto the AAV capsid surface, enhanced muscular uptake. Validation studies using Green Fluorescent Protein (GFP) as a transgene marker yielded a 15-fold increase in GFP messenger RNA levels in the quadriceps and heart in mice.
Advanced Capsid Engineering Technology
The JUST-AAV (搜索) platform utilizes modified AAV vectors with miniaturized antibodies inserted against receptors on selected tissues, organs, or the blood-brain barrier (搜索) onto the capsid surface. Through screening a library of antibody fragments, researchers identified a muscle (搜索)-targeting binder that improved muscle transduction by 2- to 3-fold compared to previous muscle-targeted AAV capsids. Characterization revealed that this binder has equal affinity for human, monkey, and mouse receptors, suggesting potential for clinical translation.
The platform incorporates both targeting enhancements and liver (搜索) de-targeting mutations on the AAV capsid. This dual approach enables precise delivery to intended tissues while minimizing accumulation in the liver, potentially improving both efficacy and safety profiles of gene therapies.
Dual-Targeting Capabilities
JCR successfully developed dual-targeting JUST-AAV (搜索) vectors by incorporating both muscle (搜索)-targeting binders and their proprietary J-Brain Cargo (搜索)® brain-targeting technology on a single capsid. This dual-targeting vector demonstrated improved transduction in both brain and muscle tissues, achieving levels comparable to AAVs with single binders.
"Our JUST-AAV (搜索) capsid engineering platform points the way toward development of new, more precisely targeted gene therapies for central nervous system (搜索) diseases that have long been considered out of reach," said Hiroyuki Sonoda, Ph.D., Director, Senior Managing Executive Officer, and Executive Director of the Research Division at JCR Pharmaceuticals (搜索). "The data presented at ESGCT demonstrate that the platform delivers therapeutic agents to the brain and muscle (搜索) far more efficiently than conventional AAV9 (搜索) capsids, while limiting accumulation in the liver (搜索)."
Clinical Applications and Future Potential
The JUST-AAV (搜索) platform encompasses a range of vector types optimized for various target tissues, including liver (搜索)-sparing, muscle (搜索)-targeting, and brain-targeting variants. The technology builds upon JCR's existing J-Brain Cargo (搜索)® platform, which has already achieved clinical success with IZCARGO® (pabinafusp alfa), approved in Japan for treating lysosomal storage disorders.
JCR Pharmaceuticals (搜索) focuses on developing treatments for rare and genetic diseases, with approved products in Japan including therapies for growth disorder, MPS II (Hunter syndrome (搜索)), Fabry disease (搜索), acute graft-versus host disease, and renal anemia. The company's investigational pipeline targets rare diseases including MPS I, MPS II, and MPS IIIA and B (Sanfilippo syndrome (搜索) types A and B).
The enhanced targeting capabilities and improved safety profile of the JUST-AAV (搜索) platform represent a significant advancement in addressing longstanding challenges in gene therapy delivery, particularly for central nervous system (搜索) and muscle (搜索) disorders that have historically been difficult to treat effectively.