How A 60-Year-Old Drug Developer Built A $4.4 Billion Biotech Treating ‘Butterfly Skin Disease’

Longtime drug developer Suma Krishnan was 51 when she cofounded Krystal Biotech. Now the company has one gene therapy on the market and more in the works.

By Amy Feldman, Forbes Staff

Longtime drug developer Suma Krishnan was in her late-40s when she had the idea for a topical gene therapy to treat a rare and terrible skin disorder in which the skin becomes as fragile as butterfly wings. In 2016, at 51, after a few months of modeling the idea and starting the process of patenting it, she…