Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

First in vivo human genome editing trial


The first patient dosed with an in vivo gene editing therapy was treated at UCSF Benioff Children's Hospital Oakland as part of Sangamo Therapeutics' clinical trial. The phase 1/2 CHAMPIONS study launched in November is an open-label trial that will evaluate single ascending IV doses of Sangamo's SB-913, a zinc finger nuclease (ZFN)-mediated gene editing therapy for treating mucopolisaccharidosis II (MPS II) or Hunter's syndrome. MPS II is a progressive inherited lysosomal storage disorder caused by mutations in the gene encoding iduronate-2-sulfatase enzyme, which degrades glycosaminoglycans. Depending on the severity of the mutation and the degree of residual enzyme activity, children with this may experience delays in cognitive development, enlarged organs, cardiovascular disorders, hearing loss, stunted growth and skeletal abnormalities, owing to a buildup of toxic carbohydrates in cells throughout their body. One in 100,000–170,000 people are estimated to be born with MPS II. The current standard of care is enzyme replacement therapy that requires regular infusions. The open-label trial will test for safety, vector clearance and the change from baseline in urinary glycosaminoglycans. Sangamo aims to use genome editing to insert a corrective gene into the precise location within the albumin gene using adeno-associated virus vectors that specifically target the liver. The ability to introduce the therapeutic gene permanently could enable a patient's liver to produce a stable supply of the missing enzyme. Sangamo's in vivo genome editing approach allows the therapeutic gene to integrate precisely into the genome, whereas conventional AAV cDNA gene therapy and lenti- or retroviral-based approaches insert randomly. SB-913 has Fast Track, Orphan Drug and rare pediatric disease designations in the US to treat MPS II. Two additional clinical trials are underway in the US to evaluate Sangamo's in vivo genome editing therapeutics for hemophilia B and MPS I, also known as Hurler or Hurler-Scheie syndrome.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

First in vivo human genome editing trial. Nat Biotechnol 36, 5 (2018).

Download citation

  • Published:

  • Issue Date:

  • DOI:

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing