Speaker: Corey Brizzee, Director, Gene Editing, Demeetra

Cas-CLOVER’s dimeric nuclease enables precise GS knockouts (Chr1 & Chr5), creating the CleanCut™ GS CHO platform. Derivative lines reduce HCP expression by disrupting 6–7 alleles in one transfection. This highlights Cas-CLOVER’s efficiency, scalability, and precision in engineering complex traits for next-gen biologics manufacturing.

With the biopharmaceutical field evolving toward increasingly sophisticated next-generation therapeutics, there is a rising demand for gene-edited cell lines that consistently yield high-quality, intact biomolecules. This presentation outlines the distinct specificity and efficiency of the dimeric Cas-CLOVER nuclease in addressing these requirements.

We present data demonstrating that Cas-CLOVER enables highly selective editing of the recently identified GS pseudogene on chromosome 1, as well as precise targeting of the primary glutamine synthetase gene located on chromosome 5. This targeted approach leads to a rigorous GS5/1 double knockout, forming the foundation of the CleanCut™ GS CHO platform.

Furthermore, a variety of derivative cell lines are being developed from the parental CleanCut™ GS CHO platform, including those designed to reduce host cell protein (HCP) expression—an important strategy for streamlining downstream purification and improving product quality. Utilizing the high editing efficiency of Cas-CLOVER, we have achieved the simultaneous disruption of multiple HCP genes (six to seven alleles) within a single transfection. These results highlight the scalability and precision of the Cas-CLOVER system for engineering complex, multi-gene traits essential to modern biologics manufacturing.