John Leonard

Gene-editing technology CRISPR is only 12 years old—still nascent in scientific terms. But after decades of working with HIV, understanding how that virus integrated itself into cells, and figuring out ways to remove it, Dr. John Leonard was perfectly positioned to use the groundbreaking technology to splice out disease-causing versions of a gene—permanently. Leonard is president and CEO of Intellia, a biotech company founded in 2014 to take advantage of CRISPR, which makes precise edits to the genomes of cells. Last October, the FDA approved the company’s plans to start advanced human testing of a CRISPR-based treatment for a hereditary condition that affects the heart and leads to frequent and debilitating pain. It’s the first trial to test CRISPR in people; previous CRISPR therapies for sickle cell disease involved editing patients’ cells outside of the body and reinfusing them into patients to seed populations of healthy cells.

The trial is a potential game changer in many ways. “We’ve established enough safety and effectiveness information to see if this will be a drug that could be available for people. That’s a big deal,” says Leonard. “For the field of CRISPR therapies as well as for us as a company.”

If the trial is successful, it will spawn a flood of CRISPR-based therapies in coming years, opening the possibility of curing certain genetic diseases. “We can do all the interesting things in the lab and that’s wonderful, but the acid test is getting a therapy approved and having doctors prescribe it for patients,” says Leonard. “We’re at the step before that for CRISPR therapies.”