MyoAAV-4E

MyoAAV-4E is an engineered, muscle-tropic adeno-associated virus (AAV) capsid designed for high-efficiency gene delivery to skeletal muscle and cardiac tissue. Developed through directed evolution by researchers at the Broad Institute (Sharif Tabebordbar et al.) and published in *Cell* in 2021, it belongs to the MyoAAV family of vectors. MyoAAV-4E contains a specific RGD-containing peptide insertion that enables it to bind with high affinity to integrins (specifically alpha-V beta-6 and alpha-V beta-8) which are expressed on muscle cells. This targeting allows for significantly enhanced potency in both mice and non-human primates compared to natural serotypes like AAV9, potentially enabling lower systemic doses and reducing off-target liver toxicity. The technology is currently being utilized by Kate Therapeutics as part of their DELIVER platform to develop gene therapies for neuromuscular and cardiac diseases, such as X-linked myotubular myopathy and myotonic dystrophy.