ASGCT 2025: Der erste Patient der Welt, der mit einer personalisierten CRISPR -Therapie behandelt wurde

Kyle’s son, KJ, was born with a rare genetic disease known as severe carbamoyl phosphate synthetase 1 (CPS1) deficiency, a metabolic disorder caused by the accumulation of toxic levels of ammonia in the blood. KJ was too young and vulnerable to receive a liver transplant—the standard-of-care option for the disease—and with each day that passed, KJ’s risk for neurological damage or death increased. CPS1 is the most severe form of urea cycle disorder with an estimated 50% mortality in early infancy.

Rebecca Ahrens-Nicklas, MD, PhD, a physician-scientist at Children’s Hospital of Philadelphia (CHOP), approached Kyle and his partner, Nicole Muldoon, with a radical idea for something that had never been done before—a personalized CRISPR therapy that could correct KJ’s individual disease-causing mutation.

KJ had become the world’s first patient to be treated with a personalized CRISPR therapy that made a correction directly to the genome.

According to Musunuru, the therapy’s cost was “not as expensive as you might think.” While the traditional road to approval for a gene editing treatment requires rigorous studies that take years to complete to demonstrate safety and effectiveness, KJ’s urgent timelines brought costs down to orders of magnitude less than standard drug development.

“Facilitating such a process could transform N-of-1 therapy into N-of-many therapies, thus leading to commercial viability of these products for rare diseases—a development that would ultimately benefit many persons with great unmet medical need,” Marks wrote in his *NEJM* editorial.