SynGenSys has launched Liver.SET, a library of liver-specific synthetic promoters designed to enable tissue-specific gene expression for in vivo gene therapies. The library is intended to provide high specificity for liver-targeted expression while minimising off-target activity in muscle tissue.

The Liver.SET library was developed using SynGenSys’ proprietary computational and informatics platform. It comprises compact, patentable synthetic promoters validated both in vitro and in vivo for liver specificity. According to the company, the promoters offer increased activity and design flexibility compared with natural liver promoters, which have fixed activity profiles, sizes and regulatory behaviours. Liver.SET promoters also exhibit low activity in HEK293 cells, reducing manufacturing challenges during viral vector packaging, while their modular design supports rapid customisation and compatibility with AAV payloads.

The launch builds on SynGenSys’ previous tissue-specific promoter library, NK.SET1, developed for natural killer cell therapies. Liver.SET further demonstrates the company’s ability to design promoters with precise tissue-specificity for therapeutic applications, including potential targeting of other tissues such as muscle, retina and central nervous system. SynGenSys said the commercial availability of validated promoter libraries highlights its capabilities for supporting safer and more effective cell and gene therapy development.

Dr Mike Daniels, chief commercial officer at SynGenSys, said: “The launch of Liver.SET™ represents another significant milestone for SynGenSys, demonstrating that our platform can deliver synthetic promoter solutions for real gene therapy development needs. We see this as a key enabler for in vivo gene therapies, and a reliable, validated starting point for deeper collaboration with developers seeking to design novel therapeutics with enhanced precision and safety.”

The company said Liver.SET is designed to provide developers with a foundation for precise, customisable gene expression in liver-targeted therapeutics, potentially improving both efficacy and safety profiles in cell and gene therapy programmes.