December 8th, 2010
PROTECT II Study of Impella Stopped Early for Futility
The PROTECT II study has been stopped early. The trial had been comparing the Impella circulatory support device to the intra-aortic balloon in high-risk PCI patients. The trial was terminated after an interim analysis by the Data and Safety Monitoring Board, which reached a “futility determination… regarding the primary end-point,” according to a press release from the trial’s sponsor, Abiomed.
In its press release, Abiomed said the source of the trial’s problem was likely an unexpected increase in the use of atherectomy in the Impella arm of the trial. The press release quoted the trial PI, William O’Neill:
“Atherectomy was an unanticipated variable which resulted from the operators’ decision to ‘do more with Impella.’ Our investigators had unblinded knowledge of the treatment arm after randomization. It is interesting that operators felt that they could do more complex interventions once randomized to Impella and this in and of itself is an important finding.”
Abiomed also claimed that a number of “encouraging results” were seen in the trial.