Glaxo says study eases concerns about Avandia

On the eve of a crucial congressional hearing, the makers of the widely prescribed diabetes drug Avandia launched a high-stakes effort Tuesday to refute evidence that their product increases the risk of heart attacks and death.

Drug maker GlaxoSmithKline said interim results from a large ongoing clinical trial found no significant difference in heart-related hospitalizations or deaths between patients taking Avandia and those on older medications for Type 2 diabetes.

“We believe these results are very reassuring to physicians and patients,” said Dr. Ronald Krall, the company’s chief medical officer.

But the findings may not clear up the uncertainty about Avandia, because Glaxo itself acknowledged in a news release that “these data do not offer final conclusions.” About 1 million patients in the United States are taking Avandia, which came on the market eight years ago.

Today, the House Oversight and Government Reform Committee is holding a hearing into the Food and Drug Administration’s handling of Avandia, after complaints from consumer groups and some lawmakers that the agency kept important early cautionary data from the public.

The FDA is planning a scientific meeting this summer to weigh the latest information about the drug’s risks and benefits. Those deliberations could prompt regulatory action ranging from stronger warnings to a ban.

The results released Tuesday come from a Glaxo-sponsored trial intended to assess the long-term cardiovascular safety of Avandia. They were published online by the New England Journal of Medicine, the same publication that only two weeks ago reported that the medication appeared to increase the risk of heart attacks by 43%. The original report was based on a statistical analysis that pooled results from 42 clinical trials comparing Avandia with another drug or with a placebo.

A spokeswoman for the journal said Tuesday’s publication of the Glaxo data did not mean editors had changed their minds about the earlier article. Indeed, a signed editorial accompanying the new findings urged doctors to remain cautious about prescribing Avandia.

“Unfortunately, this interim analysis ... fails to provide exculpatory evidence,” Dr. David M. Nathan of Massachusetts General Hospital wrote. “The interim results ... do not provide any assurance of safety of treatment” with Avandia.

Nathan, director of the Diabetes Center at Massachusetts General Hospital and a professor of medicine at Harvard Medical School, said the preliminary results lacked statistical “power,” partly because the study was not complete. And he questioned the combination of older drugs selected to compare with Avandia.

But Krall and Murray Stewart, Glaxo’s head of clinical development, said any significant differences in heart risks would in all likelihood have already emerged nearly four years into the study.

Instead, patients in the group being treated with Avandia had much the same results as those in the control group, who received older diabetes medications. The overall number of complications and deaths in both groups was low.

For example, of 2,220 patients treated with Avandia, 43 suffered heart attacks. In the control group of 2,227 patients, 37 had heart attacks.

In the Avandia group, 217 patients died or were hospitalized because of heart-related problems. In the control group, there were 202 such cases.

Patients taking Avandia were at higher risk of going into heart failure, a condition in which a weakened heart can no longer pump enough blood. But that particular risk has been known since the drug was approved in 1999, and warnings have been issued.

Stewart said an independent committee of doctors overseeing the Glaxo study urged that the data be released so patients and doctors would be fully informed. “We did not push the steering committee to publish,” he said.

Two other large studies being conducted by the National Institutes of Health may also shed light on the risks of Avandia. One involves 2,368 patients and the other has enrolled 10,251 people. NIH spokeswoman Amy Pianalto said scientists were reviewing the data from the studies but had not announced any conclusions.

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ricardo.alonso-zaldivar@latimes.com