BARCELONA, Aug 31 (Reuters) - A major clinical study has raised concerns about a drug from private French company Servier that helps lower the heart rate and which was licensed to U.S. group Amgen last year.
Ivabradine is not currently approved in the United States but it is sold in Europe for treating stable angina, or chest pain due to obstruction of heart arteries, and for heart failure, when the heart fails to pump blood effectively.
Although lowering the heart rate is seen as good for both conditions, a 19,000-patient study presented on Sunday at the European Society of Cardiology congress found a large group of patients with severe activity-limiting angina did worse on the drug.
The SIGNIFY trial had been designed to show that adding ivabradine to standard therapy would be beneficial. The negative result in the sub-group of 12,000 patients with severe angina meant it failed.
The increase in the combined risk of cardiovascular death and heart attack in this patient group was small but statistically significant, with 7.6 percent of them suffering an adverse event against 6.5 percent of those on placebo.
A commentary in the New England Journal of Medicine, where the results were also published, said more research was needed to understand the finding and in the meantime doctors should "exercise caution" in using the drug in severe angina patients.
The European Medicines Agency said in May it had launched a review into the safety of the medicine, which is sold under the brand name Procoralan, because of the signal from the SIGNIFY trial. But the detailed results have only now been released.
The agency could decide to maintain, amend, suspend or withdraw its approval for the drug.
Servier said at the time it had informed all relevant regulators about the findings and would update doctors as soon as the European agency made a decision.
Amgen, which signed a deal in July 2013 for U.S. commercial rights to ivabradine, last week won a priority review for the drug as a treatment for chronic heart failure from the U.S. Food and Drug Administration.
It is unclear what impact, if any, the SIGNIFY results might have on this heart failure application. Amgen officials were not immediately available to comment. (Reporting by Ben Hirschler; Editing by Hugh Lawson)