As reported on MedicalXpress, esearchers at the Children’s Hospital of Philadelphia (CHOP) and the University of Pennsylvania are pioneering a new approach to treating rare genetic disorders using CRISPR-based therapies. Earlier this year, the team developed a bespoke drug to correct a genetic mutation in an infant with a life-threatening liver condition, marking a breakthrough in personalized medicine.

The U.S. Food and Drug Administration (FDA) has now introduced a “plausible mechanism” protocol, enabling clinical trials for one-of-a-kind treatments like this. The framework allows researchers to test a single drug platform that can be tailored to individual patients, addressing a major hurdle in rare-disease drug development: the lack of large patient populations for traditional trials.

The Philadelphia team, led by cardiologist Kiran Musunuru and metabolic specialist Rebecca Ahrens-Nicklas, will apply the protocol to urea cycle disorders, which impair protein metabolism. Their method keeps the core CRISPR mechanism consistent while customizing the genetic correction for each patient’s mutation.

This initiative could transform the economics and feasibility of rare-disease therapies, offering a scalable model for pharmaceutical companies. While each condition is uncommon, millions of people worldwide suffer from rare diseases, many of which share genetic characteristics that could be targeted through personalized treatments.

FDA leaders highlighted the case in the New England Journal of Medicine, noting that bespoke therapies are moving closer to reality nearly three decades after the human genome was sequenced.