Editas Medicine, Inc. announced data on a new gene editing technology termed SLEEK (SeLection by Essential-gene Exon Knock-in). The Company reported these data in an oral presentation at Cold Spring Harbor Laboratory’s Genome Engineering: CRISPR Frontiers meeting, being held virtually August 18-20, 2021. Despite major progress in achieving gene disruption, efficient knock-in of transgenes continues to be a significant challenge for the gene editing field. To solve this challenge, SLEEK was developed enabling high knock-in efficiencies with different transgenes while also ensuring robust, transgene expression. Editas Medicine believes that SLEEK may enable the development of next generation cell therapeutics for cancer and other serious diseases. New preclinical data demonstrated that SLEEK results in the knock-in of multiple clinically relevant transgenes through a proprietary process that selects for cells containing the knock-in cargo. In addition, high percentage knock-in efficiencies were enabled by Editas Medicine’s proprietary engineered AsCas12a nuclease. More than 90% knock-in efficiencies were observed in various clinically relevant target cells, including iPSCs, T cells, and NK cells. Additionally, SLEEK may be used to fine-tune the expression levels of transgene cargos, an important attribute of next-generation cell therapy medicines.