Recently, US biotechnology company Prime Medicine announced that it has completed the world's first in vivo Prime Editing administration trial. This marks the first time Prime Editing technology has directly rewritten DNA in a living patient, representing a milestone event in the field of gene editing.
During the trial, they administered the experimental drug PM577a to a patient with Wilson's disease (hepatolenticular degeneration).
Wilson's disease is caused by mutations in the ATP7B gene, which prevents the liver from properly metabolizing and excreting copper. This leads to continuous copper accumulation, causing ongoing damage to the liver and nervous system. Existing treatments can only control the condition through long-term medication and cannot provide a cure. The goal of this therapy is to correct this pathogenic mutation.
Unlike CRISPR-Cas9, Prime Editing does not cut both strands of DNA. It functions more like a "find and replace" tool within the genome, relying on a Cas9 nickase paired with a reverse transcriptase to complete base modifications. Theoretically, this results in lower off-target risks and more precise editing.
The drug is delivered via lipid nanoparticles (LNPs) through intravenous infusion into the bloodstream, targeting hepatocytes to perform DNA modifications. As an in vivo editing approach, it eliminates the need to extract cells for ex vivo modification and reinfusion. If matured in the future, this method is expected to significantly reduce treatment costs and simplify procedures.
The administration took place on October 5 as part of a Phase 1/2 clinical trial. Currently, only the dosing has been completed, with safety and efficacy data yet to be released. The initial study results are expected to be published in 2027.
The patient will undergo long-term monitoring to track copper metabolism indicators, liver status, and potential side effects of gene editing.
From an industry perspective, while CRISPR-based in vivo editing therapies have already entered clinical trials, Prime Editing had remained at the laboratory stage. The implementation of this trial opens up new directions for precise single-base genetic disease treatments.
However, this therapy also carries certain risks. The long-term safety of LNP delivery and in vivo gene modification remains unknown, and there is still a lengthy clinical trial period before it can be officially marketed.