Doug Melton: A stem-cell cure for diabetes

Type 1 diabetes affects 1.25 million Americans, but two in particular got Harvard biologist Doug Melton’s attention: his daughter Emma and son Sam. Treatment can involve a lifetime of careful eating, insulin injections and multiple daily blood-glucose tests. Melton has a different approach: using stem cells to create replacement beta cells that produce insulin. He started the work over 10 years ago, when stem-cell research was raising hopes and controversy. In 2014 he co-founded Semma Therapeutics—the name is derived from Sam and Emma—to develop the technology, and this summer it was acquired by Vertex Pharmaceuticals for $950 million. The company has created a small, implantable device that holds millions of replacement beta cells, letting glucose and insulin through but keeping immune cells out. “If it works in people as well as it does in animals, it’s possible that people will not be diabetic,” Melton says. “They will eat and drink and play like those of us who are not.”—Don Steinberg