Prime Medicine Performs First In Vivo Prime Gene Edit
The clinical trial marks a transition from ex vivo cell therapies to direct DNA correction for genetic disease.
Updated on Oct. 22, 2026 in Biotech
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Prime Medicine has treated the first patient in a clinical trial using in vivo prime editing to rewrite DNA directly within liver cells. This research-stage procedure aims to correct mutations in the ATP7B gene responsible for Wilson disease.
Why it matters
In vivo editing potentially bypasses the manufacturing complexities and speed limitations of ex vivo therapies, where cells are removed from the body to be modified. Successfully rewriting DNA inside the patient could provide a durable treatment for genetic disorders like Wilson disease, which causes toxic copper accumulation.
Prime editing uses a molecular toolset to rewrite DNA sequences rather than disabling them like CRISPR-Cas9. This clinical-stage method directly targets and repairs the ATP7B gene in liver cells to restore protein function.
The players
Prime Medicine
A biotechnology company focused on developing prime editing therapies that rewrite DNA to correct genetic diseases.
FDA
The United States federal agency responsible for regulating and approving human gene-editing therapies and clinical trials.
The details
Prime editing functions as a precision word processor for the genome, allowing scientists to install specific DNA corrections. Unlike older CRISPR-Cas9 methods that create double-strand breaks to disable genes, prime editing uses a specialized protein to rewrite targeted segments of DNA. This allows the liver cells to produce the protein necessary for transporting excess copper out of the body, potentially resolving the underlying mechanism of Wilson disease.
Timeline
Earlier this month, Prime Medicine treated the first clinical trial participant.
Early next year, the FDA is expected to decide on an in vivo CRISPR-Cas9 therapy for hereditary angioedema.
Next year, Prime Medicine expects to announce initial trial results.
The Tech Race
This procedure marks a significant shift from current FDA-approved CRISPR therapies, such as Casgevy, which rely on gene disruption. By demonstrating in vivo prime editing, the effort advances the field toward precise genetic correction rather than merely disabling faulty sequences.
This procedure is currently in the initial clinical trial phase and is not available to the public. Future availability will depend on the results of ongoing safety and efficacy monitoring throughout the coming year.
The takeaway
Prime Medicine has successfully initiated the first in vivo prime editing clinical trial for Wilson disease. Observers should track the first results, expected next year, as a key benchmark for the safety and precision of direct DNA rewriting in humans.
Further reading
For broader trends in the field, explore the Biotech archive.
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Is now a good time to move forward with direct in-body human gene editing treatments?
