NEW YORK (Reuters) - The rise of serious heart risks in drugs that treat chronic conditions has become one of the U.S. Food and Drug Administration's top worries and is changing how the agency weighs new medicines, a top FDA official said on Tuesday.
The agency is thinking about how to weigh such possible side effects as more drugs that treat diabetes, pain and other conditions also appear linked to heart attacks and other complications, Dr. John Jenkins, director of the FDA's Office of New Drugs, told the Reuters Health Summit in New York.
"That has been the biggest safety shift in the last few years, and it's also, I think, a driver for a lot of the public concern about drug safety," he said.
"There have been a string of products or classes of products where we're now seeing concerns about increasing the risk of cardiovascular events," he said, citing GlaxoSmithKline Plc's (GSK.L) (GSK.N) diabetes pill Avandia, Novartis AG's NOVN.VX (NVS.N) bowel drug Zelnorm and painkillers known as COX-2 inhibitors.
Merck & Co Inc's (MRK.N) COX-2 drug Vioxx, and later Pfizer Inc's (PFE.N) Bextra, were pulled from the U.S. market in 2004 and 2005 after serious heart problems were found to outweigh their possible benefits.
In the past, patients typically took medications when they were seriously ill and known side effects were often more unusual ones such as liver failure, Jenkins said. Those were easier to link to drugs because they were less common in the wider population where heart disease is a major condition.
It is especially a concern as more Americans take drugs long-term to treat conditions such as high cholesterol, he said.
"We are thinking about what the implications of these new data and these new findings are for all chronically used drugs," he said.
As a result, Jenkins said, the FDA is thinking about which types of drugs may need to have more research on heart side effects either before or after approval.
"It's changing how we look at how much data you need to get a drug approved," he said. The agency also "might look at more requirements for large studies after approval."
For example, the agency has not typically asked makers of rheumatoid arthritis drugs to present heart data from large clinical trials, Jenkins said. But "patients with rheumatoid arthritis have an increased risk of cardiovascular disease, so we have to start thinking about those issues."
He added the agency has not yet taken any steps to require such information for those drugs.
The agency has said it plans to give specific advice to drug makers about what kinds of data they will need to sell diabetes drugs in the United States.
Several drug makers, including Glaxo, Bristol-Myers Squibb Co (BMY.N), AstraZeneca Plc (AZN.L) (AZN.N), Eli Lilly and Co (LLY.N) and Amylin Pharmaceutical Co AMLN.O, are developing new diabetes drugs.
The FDA's recommendations, or guidelines, on diabetes drugs will be released "very soon," Jenkins said.
In July, an FDA panel of outside advisers said companies should have to conduct long-term studies of cardiovascular effects or provide equivalent evidence to rule out an "unacceptable" risk of heart problems.
Concern that diabetes medicines may damage the heart arose last year when a study by Cleveland Clinic researchers found Glaxo's Avandia increased the chances of a heart attack. The drug now carries a prominent boxed warning on its label to caution doctors and patients about the risk.
(For summit blog: summitnotebook.reuters.com/))
Additional reporting by Lisa Richwine; Editing by Carol Bishopric, Phil Berlowitz