Bioengineering of phage-derived particles as a discovery platform for muscle gene therapy

PROJECT SUMMARY Gene therapy provides a functional cure for patients with genetic disorders and is particularly relevant to the treatment of monogenic rare diseases (those caused by a single gene), such as Duchenne muscular dystrophy (DMD). Adeno-associated virus (AAV) is the most prevalent and clinically successful viral gene therapy. However, as a delivery platform, it exhibits significant limitations when it comes to immunogenicity, cargo ca- pacity, manufacturability, and ease of cell type-specific targeting. Other platforms, such as lipid nanoparti- cle/mRNA formulations, can be manufactured at scale but only induce untargeted and transient gene expres- sion. Therefore, while each has its strengths and weaknesses, there is currently no platform available that brings accessible and durable gene therapy to rare genetic disorders. The goal of M13-Tx is to develop a next-generation in vivo gene delivery platform that addresses the current key limitations of existing gene therapy technologies. This platform is based on phage-derived particles (PDPs) – an immune-privileged, easily engineerable, and efficiently produced derivation of M13 bacteriophage – spe- cifically designed for the transduction of human cells. By the combination of directed evolution and rational de- sign, these PDPs can be engineered to target any tissue and deliver up to 20kb DNA cargo. In this Phase I SBIR, M13-Tx proposes to engineer and screen PDPs to successfully deploy a cargo carrying the functional copy of DMD gene coding for dystrophin protein in muscle tissue in vivo. In contrast to existing AAVs, which can only pack a fraction of the DMD coding sequence, the PDPs will deploy the full DMD gene only in muscle tissue for durable and redoseable treatment of Duchenne muscular dystrophy. The final product of this proposal is lead PDPs, ready to be tested in the DMD mouse model. The lead PDPs and muscle-specific deployment can be utilized across rare diseases caused by mutations of different genes but manifested in the same tissue (e.g., Myotonic Dystrophy and Facioscapulohumeral Muscular Dystrophy). Moreover, the same workflow can be used to find PDPs for other difficult-to-target tissues (e.g., lung and CNS). The proposed study will serve as a proof-of-concept, showing that PDPs can be selected for specific gene delivery purpose, given their engineerable coat and easily modified cargos. Developing this technology will revolutionize gene therapy by presenting a versatile and affordable gene delivery platform.