U.S. biotechnology company Prime Medicine announced that it has used prime editing technology to directly edit DNA in a human body for the first time, treating a patient with Wilson’s disease. Initial clinical trial results are expected to be announced in 2027. Prime editing is regarded as a next-generation gene-editing tool. By combining a Cas9 nickase with reverse transcriptase, it can achieve base substitutions, small insertions, and deletions without cutting both DNA strands. Compared with the traditional CRISPR-Cas9 “cut-and-repair” approach, prime editing is more like executing a “find-and-replace” in the genome, with higher precision and fewer byproducts. This trial involved in vivo gene editing. The team delivered prime editing components into the patient’s liver cells via lipid nanoparticles to correct a specific mutation in the ATP7B gene. Unlike ex vivo editing, in vivo editing does not require extracting patient cells, modifying them in the laboratory, and reinfusing them, so it is expected to lower manufacturing and logistical costs and make treatment easier to promote.