In a major milestone for biotechnology, prime editing has been used to modify DNA directly inside a human patient's body. The procedure represents the first known instance of such a treatment, marking an advance in the clinical development of genetic medicine.
The milestone occurred as part of an active clinical trial conducted by Prime Medicine, a biotechnology company based in Cambridge, Massachusetts. The company announced earlier this month that it had treated its first participant using prime editing, an approach capable of performing fine-scale alterations to DNA sequences with greater precision than traditional CRISPR–Cas9 tools.
The trial specifically focuses on Wilson disease, a condition caused by mutations in a gene called ATP7B. This gene encodes a protein responsible for transporting excess copper out of the liver. The experimental prime editing therapy directly rewrites DNA inside liver cells to erase the mutation that prevents them from eliminating excess copper.
Rewriting DNA directly in the body, or in vivo, offers distinct practical advantages over custom cell-based therapies. Administering and manufacturing treatments inside the body might be much cheaper and faster than making a bespoke therapy for each person from their own cells. So far, the US Food and Drug Administration has approved only one gene-editing therapy, Casgevy, which is used to treat two inherited blood disorders.
As this clinical trial advances with its first treated participant, the findings will provide insight into how fine-scale genetic corrections function directly within human organs. How significantly might in vivo prime editing change the landscape of treating inherited genetic disorders?
