The first human trial using embryonic stem cells has been delayed by the U.S. Food and Drug Administration, the Geron Corporation announced Tuesday.
The company wants to study whether injecting nerve cells made from embryonic stem cells into the site of spinal injuries can help restore movement in paralyzed people. But the FDA refused to allow the study to proceed after Geron provided data from dose escalation studies in animals, Bloomberg news reported.
California-based Geron said it "will work closely with the FDA to facilitate their review of the new data and to release the clinical hold."
Thousands of people around the world have been treated with adult stem cells, with mixed results. But no approved trial has tested embryo-derived stem cells in humans, Bloomberg reported.