April 15, 2015
FDA Should Again Reject Medication for Preventing Blood Clots in Patients Undergoing Cardiac Procedures, Public Citizen Tells Advisory Committee
New Analyses of Same Unethical Trial Does Not Provide Substantial Evidence That Cangrelor Is Effective
WASHINGTON, D.C. – The evidence regarding the safety and effectiveness of the blood clot-reducing medication cangrelor is just as poor now as it was last year when the U.S. Food and Drug Administration (FDA) rejected it, and the agency should reject it again, Public Citizen said in testimony today.
New analyses of the same unethically conducted key clinical trial – called the Champion Phoenix trial – reviewed last year still lack substantial evidence that the medication is effective, Public Citizen said.
Cangrelor, a treatment designed to prevent blood clots during heart artery-clearing angioplasty and stenting procedures, was rejected by the FDA in April 2014, following a February FDA advisory committee vote against approval. However, its manufacturer, The Medicines Company, has resubmitted the new drug application for reconsideration by the FDA.
Testifying today before the FDA’s Cardiovascular and Renal Drugs Advisory Committee, Dr. Michael Carome, director of Public Citizen’s Health Research Group, strongly urged the committee to reject cangrelor, because the new analyses provided by The Medicines Company still are based on data from the same clinical trial that was poorly and unethically conducted.
“The Medicines Company obviously is desperate to obtain FDA approval for cangrelor. But providing more analysis of the same flawed trial does not address the problems with how the trial was originally conducted,” said Carome. “During the first application, the FDA’s own lead medical reviewer wrote a scathing review and recommended that the treatment not be approved because he considered the three major trials submitted with the application to be insufficient to prove the medication’s effectiveness, as well as unethical. Since no new trials have been conducted, the FDA should once again reject cangrelor.”
During the main clinical trial, many subjects in the control group received substandard care, and as a result, the trial failed to provide substantial evidence that cangrelor is as safe or effective as other available treatments recommended by expert guidelines. For example, subjects randomly assigned to the control group received clopidogrel. This medication is routinely given before cardiac stent procedures to prevent clot formation in the stent and heart attacks during the procedure. However, more than a third of these control subjects received the medication after the procedure began or when it was over, likely resulting in a larger number of clots and heart attacks in control subjects during or immediately after the stent procedure. In contrast, nearly all subjects in the cangrelor group received the drug before the stent procedure began.
The fact that the subjects were given substandard care is one factor that made the trial unethical. In addition, the consent forms at some trial sites appear to have failed to adequately describe to subjects the risks of participating in the trial relative to guideline-recommended care or to inform subjects of alternative courses of treatment that might have been more effective.