The world’s first bespoke gene therapy saved the life of a newborn with a rare genetic disorder that cause the build-up of life-threatening ammonia in the body. In a race against time, scientists and doctors across the U.S. developed the first in vivo gene therapy, thanks to decades of medical research. After three doses, the newborn patient showed drastic improvement, and this new era of in vivo gene therapies could save the lives of millions more in the future. inside a living organism, rather than in a petri dish) CRISPR gene therapy. “The promise of gene therapy that we’ve heard about for decades is coming to fruition, and it’s going to utterly transform the way we approach medicine.”