This is a compact, single adeno-associated virus (AAV) vector that switches on a patient’s own LAMA1 gene, a compensatory laminin, using a miniaturized CRISPR activation system. In disease-model mice, the approach restored laminin-α1 in muscle and nerve and improved survival, body weight and motor function.
Description
Unmet Need - There is currently no cure for congenital muscular dystrophies, and earlier CRISPR activation systems needed two AAV vectors, while this single-vector design delivers the full system in one AAV at a lower dose.
The vector packages everything needed to turn up the LAMA1 gene between two AAV end sequences. A guide RNA directs a catalytically inactive Cas protein, one that no longer cuts DNA, to the region just upstream of the LAMA1 start site. The Cas protein carries transcriptional activators that boost the gene’s own expression. Because the endogenous gene is activated rather than replaced, the cell makes laminin-α1 from its own genomic copy.
The key innovation is a very short synthetic promoter of only 78 nucleotides. It is built from at least four repeated NRF1-type binding motifs separated by 8 to 12 nucleotides, and it drives the Cas-activator component. This small size lets the guide RNA and the Cas-activator fit into a single AAV genome. The specification shows that this promoter works in muscle cells, fibroblasts and Schwann cells, and that expression is detected across tissues after systemic delivery.
Applications
- Gene therapy for LAMA2-related congenital muscular dystrophy
- Treatment of muscular dystrophy in skeletal muscle and peripheral nerve
- Compact single-AAV delivery platform for other CRISPR-activation therapies
- A miniaturized promoter and activator cassette for licensing into other size-limited AAV programs
- In vitro host cells for research and screening in muscle, fibroblast, Schwann and epithelial cell types
Advantages
- One AAV vector carries the complete activation system, avoiding the dual-vector requirement of earlier systems.
- Western blot analysis showed 1.88-fold higher laminin-α1 protein than the earlier system.
- Comparable laminin-α1 upregulation was achieved at a dose roughly 15 times lower than the earlier system.
- Treated dystrophic mice survived through the study, while untreated or control mice did not, and the mice also gained body weight.
- Motor, strength and nerve-myelination measures improved, with some reaching wild-type levels.
Invention Readiness
The technology has been validated in cultured mouse and human cells and in a mouse model of LAMA2-related muscular dystrophy. Delivery was tested by local injection and by systemic injection, given either at birth (prevention) or at one week of age (delayed treatment). It was evaluated for laminin-α1 expression, muscle and nerve histology, survival, body weight, grip strength, tetanic force and open-field activity. Dose titration showed efficacy at lower viral loads, and transcriptomic analysis confirmed strong, selective LAMA1 upregulation. Further studies are needed in IND-enabling safety, toxicology and biodistribution, optimization of dose and formulation, long-term durability, and testing in additional models ahead of clinical translation.
IP Status
https://patents.google.com/patent/US20240285801A1
