The world’s first authorized test in people of a treatment derived from human embryonic stem cells has been cleared to begin by the Food and Drug Administration.
The trial will test cells developed by Geron Corporation and the University of California, Irvine in patients with new spinal cord injuries.
The F.D.A. had initially cleared the clinical trial in January, 2009, in what was viewed at the time as a research milestone.
But before the study could begin, the agency then put a so-called hold on the trial after cysts were discovered in some mice injected with the cells. Geron had to do another mouse study and develop better ways to check the purity of its cells.