Late last year, dozens of researchers spanning thousands of miles banded together in a race to save one baby boy’s life. The result was a world first: a cutting-edge, gene-editing therapy fashioned for a single person, and produced in a record-breaking six months1.
Now, baby KJ Muldoon’s doctors are gearing up to do it all over again, at least five times over. And faster.
The groundbreaking clinical trial, described on 31 October in the American Journal of Human Genetics2, will deploy an offshoot of the CRISPR–Cas9 gene-editing technique called base editing, which allows scientists to make precise, single-letter changes to DNA sequences. The study is expected to begin next year, after its organizers spent months negotiating with US regulators over ways to simplify the convoluted path a gene-editing therapy normally has to take before it can enter trials.
Developing KJ’s treatment was “a pretty hectic and intense six months”, says Kiran Musunuru, a cardiologist at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, and one of KJ’s doctors. “But I think we can get it shorter.”