We selected our programs to unlock the next frontier of genetic medicine.


Our programs are currently focused on developing in vivo gene insertion therapies for the treatment of rare pediatric liver diseases: indications where traditional gene therapy approaches have failed to produce durable responses, given the rapid cell division in children’s livers. We will initially focus on developing ARCUS®-mediated therapeutic candidates, but we will continually evaluate new technologies and new therapeutic areas.

Therapeutic area



Phase 1/2

Phase 2

iECURE Programs

Urea Cycle Disorders


Citrullinemia Type 1

Preclinical OTC
Discovery Citrullinemia Type 1

Other Liver Disorders


Undisclosed indication

Discovery PKU
Discovery Undisclosed indication

Partnered Program



Preclinical PCSK9-Knockout
  • Wang, L., et al. Meganuclease targeting of PCSK9 in macaque liver leads to stable reduction in serum cholesterol. Nat Biotechnol 36, 717-725 (2018).

  • Breton, C., et al. ITR-Seq, a next-generation sequencing assay, identifies genome-wide DNA editing sites in vivo following adeno-associated viral vector-mediated genome editing. BMC Genomics 21, 239 (2020).

  • Wang, L., et al. A mutation-independent CRISPR-Cas9-mediated gene targeting approach to treat a murine model of ornithine transcarbamylase deficiency. Sci Adv 6:eaax5701. (2020).

Urea Cycle Disorders

The urea cycle is a series of biochemical reactions that converts highly toxic ammonia – a waste product of protein metabolism – to urea. In individuals affected with a urea cycle disorder, the gene coding for one of the critical enzymes in the cycle has lost function. Without the functional enzyme, the effects are devastating. Ammonia builds up in the bloodstream, causing brain damage, coma and eventually death.

Using our gene editing technology, we are currently pursuing long-lasting treatments for two urea cycle disorders: ornithine transcarbamylase (OTC) deficiency and citrullinemia type 1 (argininosuccinate synthase or ASS deficiency).

Additional Disorders

In addition to urea cycle disorders, we are advancing our gene editing technologies in other liver disorders. Our initial focus is phenylketonuria, an inborn deficiency in phenylalanine hydroxylase (PAH), which is the enzyme needed to metabolize the amino acid phenylalanine. This is a life-threatening disease that, when left untreated, leads to severe developmental delays in children.

Familial Hypercholesterolemia (FH)

As part of our development and licensing agreement with Precision BioSciences, we have agreed to fund and manage the development of an ARCUS-based genome editing therapeutic to treat familial hypercholesterolemia (FH) through the completion of a Phase 1 clinical trial. FH is a genetic disorder that causes LDL cholesterol (the “bad” form) to accumulate in very high concentrations in the bloodstream, leading to serious problems such as heart attacks and strokes, even in children.