The Medical RevolutionWhere are the cures promised by stem cells, gene therapy, and the human genome?

By Emily Yoffe

Illustration by Rob Donnelly. Click image to expand.Dr. J. William Langston has been researching Parkinson’s disease for 25 years. At one time, it seemed likely he’d have to find another disease to study, because a cure for Parkinson’s looked imminent. In the late 1980s, the field of regenerative medicine seemed poised to make it possible for doctors to put healthy tissue in a damaged brain, reversing the destruction caused by the disease.

Langston was one of many optimists. In 1999, the then-head of the National Institute of Neurological Disorders and Stroke, Dr. Gerald Fischbach, testified before the Senate that with “skill and luck,” Parkinson’s could be cured in five to 10 years. Now Langston, who is 67, doesn’t think he’ll see a Parkinson’s cure in his professional lifetime. He no longer uses “the C word” and acknowledges he and others were naive. He understands the anger of patients who, he says, “are getting quite bitter” that they remain ill, long past the time when they thought they would have been restored to health.

The disappointments are so acute in part because the promises have been so big. Over the past two decades, we’ve been told that a new age of molecular medicine—using gene therapy, stem cells, and the knowledge gleaned from unlocking the human genome—would bring us medical miracles. Just as antibiotics conquered infectious diseases and vaccines eliminated the scourges of polio and smallpox, the ability to manipulate our cells and genes is supposed to vanquish everything from terrible inherited disorders, such as Huntington’s and cystic fibrosis, to widespread conditions like cancer, diabetes, and heart disease.