A drug made by Novartis AG to treat acute heart failure should not be approved because there is insufficient evidence it improves symptoms, a panel of advisers to the U.S. Food and Drug Administration concluded on Thursday.
The panel's vote was unanimous. The FDA is not obliged to follow the advice of its advisory panels but typically does so.
Novartis filed for approval of the drug, serelaxin, based on a single study that showed that when given alongside standard treatment it alleviated shortness of breath by slowing the rate of worsening heart failure following hospitalization.
Panelists said that while the drug may have reduced worsening heart failure, additional study would be needed to determine the magnitude of the effect.
The trial did not prove the drug significantly improved shortness of breath either, they said, though the failure may have had more to do with the design of the trial than the drug itself.
Tim Wright, global head of development at Novartis, said in a statement that the panel discussion "provided important information that we will address with the FDA as it completes its review."
"In the meantime, we'll continue to drive our robust clinical trial program and build upon the already established body of evidence," he added.
The FDA generally requires evidence from two independent trials to show an improvement in symptoms. This week reviewers for the FDA recommended the drug not be approved, saying the data did not provide "persuasive evidence" of an effect on shortness of breath, or dyspnea.
Neither did data support Novartis's claim that the drug reduced the rate of worsening heart failure, the said.
The panel's recommendation echoed that of European regulators who also ruled against the drug. Novartis has requested that serelaxin be given conditional approval pending the results of a second trial designed to show its impact on mortality.
Initial data shows the drug reduced deaths by 37 percent compared with patients in the control group after six months of treatment. The company hopes to confirm that in an additional study.
About five million people in the United States are living with chronic heart failure, a progressive weakening of the heart, according to Novartis. About one million are hospitalized with episodes of acute heart failure, and about 22 percent of patients who are hospitalized die within a year.
If approved, the drug is expected to generate sales of $713 million by 2018 according to the average estimate of five analysts polled by Thomson Reuters.
The FDA is scheduled to make its decision on the drug, which would be called Reasanz if approved, by May 17.
(Reporting by Toni Clarke in Washington; Editing by Steve Orlofsky and James Dalgleish)