Doctors get good and bad safety news on diabetes drugs

Diabetes pills known as DPP-4 therapies got a mixed safety report on Monday as studies showed they did not raise the risk of heart attacks but might be linked to heart failure, where the heart fails to pump blood adequately.

Reassuringly, the medicines were not associated with increased rates of either inflammation of the pancreas or cancer - something that has been a worry in the past.

However, in the case of AstraZeneca and Bristol-Myers Squibb's approved drug Onglyza, there was a small increase in hospitalizations for heart failure.

"It is a little bit concerning," said Dr. Christopher Grainger of Duke University Medical Center, who was not involved in the research. "I'm sure the FDA (U.S. Food and Drug Administration) will want to know more about it."

Citigroup analyst Andrew Baum, who forecasts Onglyza sales of $2.47 billion in 2018, said the latest data would not ameliorate growing pressures on the DPP-4 drug class in terms of winning reimbursement and achieving wider use.

Doctors and regulators are wary of the cardiovascular safety profile of diabetes drugs following past problems, including with GlaxoSmithKline's Avandia pill, since patients with diabetes are at increased risk of heart troubles.

Researchers from Brigham and Women's Hospital in Boston, who studied Onglyza over two years in 16,492 patients, said the heart failure finding was unexpected and deserved further investigation.

AstraZeneca and Bristol had already given headline results from the study in June, showing Onglyza did not increase heart attack risk - although it did not reduce it either, as the companies had initially hoped.

To date, researchers have been unable to identify any diabetes drug that is not only safe but actually beneficial to the heart.

Some doctors were disappointed that Onglyza and Takeda's rival drug Nesina did not reduce heart risks. However, Dr. Heinz Drexel, a heart specialist at Feldkirch Hospital in Austria and a spokesman for the European Society of Cardiology (ESC), said the idea of such a benefit from taking the medicines was "not logical".

Drexel said DPP-4s still offered several advantages, including a lack of weight gain seen with some other antidiabetics, which would offset the heart failure worries.

NO OVERALL INCREASE

Detailed results of the Onglyza study were presented at the ESC annual congress in Amsterdam, alongside a 5,380-patient study of Nesina. Both studies showing no overall increase in cardiovascular risks were published simultaneously in the New England Journal of Medicine.

The co-principal investigator on the Onglyza study, Dr. Deepak Bhatt, said he believed the heart failure issue seen with Onglyza was very likely a class effect common to all DPP-4s, adding it had probably not shown up in the Nesina trial because it was far smaller.