ASGCT24: Prime Medicine to Apply Gene Editing to Wide-Ranging Indications

Pictured: 3D illustration of a DNA double-helix/iS

Pictured: 3D illustration of a DNA double-helix/iS Images/iStockphoto

The biotech touted its prime editing technology at ASGCT on Tuesday after receiving FDA clearance last week for a clinical study of a drug candidate based on the platform.

Pictured: 3D illustration of a DNA double-helix/iStock,

Fresh off of last week’s FDA clearance of a clinical trial for an ex vivo prime editing candidate in patients with a rare disease, Prime Medicine on Tuesday laid out its vision for the next generation of one-time curative gene editing therapies at the American Society of Gene & Cell Therapy’s annual meeting in Baltimore.

At a workshop on the delivery and development of precision genome editing technologies, Prime Medicine presented preclinical data the company said demonstrated the broad potential of prime editing technology.

Prime Medicine’s approach leverages CRISPR technology to rewrite defective genes without breaking both strands of the DNA double helix. According to Jonathan Levy, the company’s principal scientist for platform delivery innovation, prime editors have the capability to repair almost all types of genetic mutations and work in many different tissues, organs and cell types, with potential opportunities across thousands of indications.

“Off-target editing is very low,” Levy said in his Tuesday presentation on the development and delivery of prime editors. “In fact, for our lead programs, we show no detectable off-targets.”

First discussed in a Nature paper in 2019, the technology now includes dual-flap prime editors for larger insertions and deletions as well as Prime Assisted Site Specific Integrase Gene Editing (PASSIGE), a system that integrates large genetic payloads by leveraging a recombinase target sequence. With these platforms, the company is working on a pipeline of investigational therapeutic programs in hematology, immunology, liver, lung, ocular and neuromuscular diseases.

The Cambridge, Mass.–based biotech on April 29 announced that the FDA has cleared a study of a drug candidate based on its prime editing platform, marking the first time the agency has greenlit the use of the genetic technology in humans. Prime Medicine will report initial data next year from the Phase I/II trial of PM359, its ex vivo candidate designed to correct a prevalent disease-causing mutation of the rare inherited hematologic disorder chronic granulomatous disease.

Prime Medicine is using delivery vehicles that include electroporation, lipid nanoparticles (LNPs) and adeno-associated viruses (AAVs). The company is pursuing novel LNPs by tapping a proprietary library of more than 800 lipids.

“We’re very excited about the potential of novel LNPs for hepatic and non-hepatic delivery,” Levy said, with the goal of a universal LNP for potential use across multiple indications.

In January 2024, Prime Medicine received $15 million from the Cystic Fibrosis Foundation to support the development of prime editors for the treatment of cystic fibrosis (CF).

Under the agreement, the company is aiming to use “hotspot editing” and PASSIGE to address nearly all people with CF with a single superexon insertion strategy, which it claims has the potential to restore CF transmembrane conductance regulator (CFTR) expression in individuals’ lung cells under native expression conditions regardless of the underlying CFTR mutation.

Greg Slabodkin is the news editor at BioSpace. You can reach him at Follow him on LinkedIn.