According to Robert Lanza, chief scientific officer at biotechnology firm Advanced Cell Technology (ACT) in Santa Monica, California, iPS-cell studies like Takahashi’s could be premature. “I cannot imagine any regulatory agency permitting such a trial without years of extensive pre-clinical testing,” he says. ACT is racing to start a less-ambitious clinical trial of iPS cells for use in other diseases. Its study would inject healthy patients with platelets derived from iPS cells and from embryonic stem cells to see if they act like normal platelets, which could open the way to a treatment for blood-clotting disorders. Because platelets lack a nucleus, there is no risk of forming tumours, explains Lanza. He will meet with the US Food and Drug Administration later this month, and hopes to get approval to start the trial this year.
Lanza says that using iPS cells that contain a nucleus in human trials is “a far greater challenge” than his approach. But Takahashi’s team is prepared, counters Pera. They are “among the pioneers in this field”, he says, adding that they are “well placed to undertake these studies”.