// Aug 2026
Targeted Gene Insertion Needs More Than One Tool
Targeted large gene insertion is becoming one of the most important frontiers in genomic medicine. Many therapeutic applications benefit from or require inserting a full gene into a defined genomic location.
In many oncology or autoimmune therapies, this technology enables delivery of CARs. It also matters in monogenic disease, where inserting a functional gene may address multiple disease-causing variants with one therapeutic strategy.
The Field Needs Fit-for-Purpose Insertion Systems
Large gene insertion is not one problem. Payload size, delivery, genomic target access, insertion efficiency, specificity, and fit for either in vivo or ex vivo use are important considerations for the correct approach. No single enzyme class can address all potential applications.
Large serine recombinases (LSRs), CRISPR-LSR systems, and retrotransposons each bring different strengths. LSRs can insert large cargo without exposed double-strand breaks and are not limited by payload size. Retrotransposons offer an all-RNA delivery path. CRISPR-LSR approaches can make insertion more programmable, but with added complexity that may be better suited for ex vivo engineering.
The right question is not which modality is best. It is which modality best fits the biology, delivery route, target site, and development path.
Enzyme Diversity Creates More Paths to Success
Large insertion becomes more powerful when developers are not limited to a small set of naturally known enzymes. ElevateBio has built a discovery and engineering pipeline designed to expand that starting set.
Using a catalog of more than 10 billion proteins, ElevateBio mined more than 30,000 LSR candidates, and identified more than 100 active LSRs. Many demonstrated higher activity than the literature benchmark Bxb1 (view presentation and data).
This breadth creates optionality. Different LSRs have different recognition sites, activity levels, and integration profiles. A larger enzyme set gives developers more chances to find an insertion system that fits the therapeutic program instead of forcing the program to fit the tool.
Programmability Is the Next Barrier
LSRs are limited by the sites where they naturally integrate their cargo. Most natural or un-engineered LSRs do not have the desired insertion profiles into human genomes needed for therapeutic applications, which means the LSR technology cannot become broadly useful until engineered. ElevateBio is applying active learning, rational design, directed evolution, and generative AI to improve enzyme performance. The long-term goal is straightforward: choose the desired insertion location, then engineer or design an enzyme system matched to that site.
By leveraging our proprietary CRISPR technology to install landing pads, ElevateBio can make LSR-mediated large insertion programmable at defined genomic sites. We developed this CRISPR LSR approach in primary T cells and have shown installation of LSR landing pad with greater than 90% efficiency at the TRAC locus. Addition of our LSR components achieved 67% installation of a CD19 CAR under the endogenous TRAC promoter. This approach is an attractive avenue for ex vivo manufacturing applications that require superb programmability.
The Future Is Fit-for-Purpose Insertion
A potent and diverse targeted insertion platform gives developers multiple paths to the same goal: inserting the right cargo, at the right site, in the right cell type, using a system matched to the therapeutic need.
Large gene insertion is not just another editing modality. It is a way to expand what genomic medicines can be designed to do.
David Wiley, Director, Nucleic Acid Technology
David Wiley is the Director of Nucleic Acid Technology at ElevateBio. His work focuses on guide RNA engineering, mRNA engineering, and production optimization, and he is currently leading the development of next-generation large gene insertion technologies, focusing on R2 retrotransposons and large serine recombinases technology.
Before ElevateBio, David was at Prime Medicine, where he led efforts in pooled screening platform development and early mRNA optimization. Prior to that, he was at Vertex Pharmaceuticals, working in the Functional Genomics group to identify potential therapeutic targets using CRISPR-based pooled screening approaches.
David earned his B.S. in Cell Biology and Genetics from the University of Georgia and his Ph.D. in Cell and Molecular and Developmental Biology from the University of North Carolina at Chapel Hill. He completed his postdoctoral training at Boston Children’s Hospital.
In his free time, David enjoys carpentry and spending time outdoors.
