ARCUS is a novel, highly precise and versatile genome editing technology for DNA genome insertion, deletion, and repair

ARCUS is a proprietary genome editing technology discovered by scientists at Precision BioSciences. We currently have in vivo gene editing programs in preclinical development.

ARCUS is based on a naturally occurring genome editing enzyme, I-CreI, that evolved in the algae Chlamydomonas reinhardtii to make highly specific cuts and DNA insertions in cellular DNA. I-CreI is a member of a larger class of enzymes called homing endonucleases or meganucleases.

Given the unique advantages for ARCUS, including the cut, size, and simplicity, program development will focus on sophisticated edits. Wholly owned programs include:

is being developed for the treatment of patients with chronic hepatitis B, with submission of a clinical trial application (CTA) and/or investigational new drug (IND) application targeted for 2024. During the R&D Day, Precision will show data highlighting the potential of PBGENE-HBV to eliminate covalently closed circular DNA and inactivate integrated hepatitis B virus (HBV) DNA to drive durable antigen loss, leading to a potential functional cure.

HBV Expert Perspectives

is being developed as a first-in-class opportunity for treatment of m.3243 associated primary mitochondrial myopathy. Mitochondrial diseases are the most common hereditary metabolic disorder, affecting 1 in 4,300 people. PMM currently lacks a curative treatment and impacts approximately 50% of patients navigating mitochondrial disease. The high specificity and single component nature of Precision’s mitoARCUS nucleases are designed to enable specific editing of mutant mitochondrial DNA while allowing the normal (wild-type) mitochondrial DNA to repopulate in the mitochondria and restore normal function. Precision expects to file a CTA and/or IND in 2025.

Mitochondrial Myopathy Expert Perspectives

What differentiates ARCUS genome editing?


Our platform and products, including ARCUS nucleases are protected by a comprehensive IP portfolio with more than 95 patents to date.


ARCUS isn’t limited to deletions. ARCUS can perform complex edits, including gene insertion, gene repair, and gene deletions.


ARCUS doesn’t generate truly random DNA breaks. ARCUS is only active in the presence of its desired target DNA site.


ARCUS is one-fifth the size of CRISPR Cas9 and compatible with essentially any delivery strategy.

One Polypeptide

ARCUS is a single protein expressed from a single gene. There’s no need to deliver multiple parts. This enables efficient multiplexing of edits.


Matched 4 base pair 3′ overhangs result in predictable and detectable removal of DNA.