CRISPR gene-editing tool used inside humans for the first time

The first trial of a CRISPR-based therapy to treat inherited blindness.

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Jackson Ryan
2 min read

Doctors performing eye surgery.


In a world first, CRISPR, the powerful gene-editing tool that can cut and paste DNA, has been used inside the human body for the first time. Scientists at the Casey Eye Institute at Oregon Health & Science University, Portland, have administered a new CRISPR-based medicine to treat an inherited form of blindness, according to the two biotech companies which make the treatment.

"This dosing is a truly historic event -- for science, for medicine, and most importantly for people living with this eye disease," said Cynthia Collins, president and CEO of Editas Medicine, a gene-editing company headquartered in Massachusetts.

The breakthrough trial aims to test an experimental treatment for the genetically-inherited disease Leber congenital amaurosis 10. The disease is caused by a faulty gene that causes blindness from birth or during the first few months of life and affects around one in every 40,000 births. There are currently no approved treatment options.

The first patient in the trial received a dose of the experimental drug, called AGN-151587, via an injection in the eye. The idea is that it delivers the gene-editing tool CRISPR directly to cells in the eye which are affected by the genetic disease. CRISPR is able to find its way into those cells and correct the gene -- a cut-and-paste scenario that sees a tiny DNA edit made to remove the mutation.

Importantly, the CRISPR edit is permanent, which means patients may only need a single dose and be set for life.

The trial is expected to enroll 18 patients in total and will look at different doses of the experimental drug, refining how much is necessary to achieve the goal of reversing blindness -- without any side effects. Information about the first patient is scant, with researchers staying silent on patient information and when the surgery officially occurred.

Watch this: CRISPR explained with crisps (and assorted snacks)

CRISPR has also been at the center of human gene-editing before. In November 2018, Chinese scientist He Jiankui revealed he had created the first CRISPR-edited human embryos and they had been carried to term, resulting in the birth of two girls. The scientific community were outraged by He's work, which was later shown to have skirted numerous ethical and regulatory approvals.

The technology has been floated as a potential tool that may bring the woolly mammoth back from the dead, change agricultural practices and even eradicate entire species.

Scientists have been working to refine the ability of gene-editing tools like CRISPR to accurately and efficiently edit DNA. In October last year, a team of researchers at Harvard University unveiled a breakthrough technology called "base editing."