Scientists are preparing the first human tests of stem cell treatments—and they're nervous about it. They plan to inject cells into patients with spinal cord injuries and progressive blindness, a move that, based on animal trials, should improve the patients' condition. But those involved still fear anything less than positive results will spell disaster for the field, especially after the sudden cut off of federal funding last week. "We desperately need to know how these cells are going to perform in the human setting," one scientist tells the Washington Post. "But are we transplanting cells that are going to cause tumors?"
The trials are privately funded and government-sanctioned, and extensive lab experiments were required by the FDA in advance of using humans. Only adults will be considered, and many precautions are being taken. Even so, "there's a lot of angst around these trials," says another researcher—if stem cells hurt patients, or just do nothing, it could torpedo funding. But "if we're right," says one CEO whose company is studying paralyzed patients, "we'll revolutionize the treatment of many chronic diseases."