Researchers at Brigham and Women’s Hospital in Boston who conducted the study also found an increase in hospitalizations for heart failure among those who took the drug, compared to those who did not. The study findings may help to “guide physicians and improve their ability to prescribe different diabetes drugs in a more evidence-based and data-driven way,” researcher Deepak Bhatt said in a statement.
The study was funded not by the federal government or other sources but by the drug makers, AstraZeneca and Bristol-Myers Squibb, based in London and New York City respectively. Bhatt and his colleagues published the study in a major peer-reviewed journal on Monday, presenting their results at the annual meeting of the European Society of Cardiology in Amsterdam.
An editorial accompanying the journal article highlighted safety concerns for diabetes drugs, noting that the commercially successful Avandia had been mostly pulled from the U.S. market in 2010 for safety reasons. That drug won approval from American regulators in 1999, after which a review of studies in 2007 showed a 43 percent increase in heart attacks as well as a 64 percent increase in cardiovascular mortalities, both of which were linked to Avandia. Subsequently, the U.S. Food and Drug Administration changed tacts with diabetes drugs, requiring not only pre-approval study but also post-approval research on all new diabetes drugs with regard to cardiovascular risk.
Thus, the approval of Onglyza, known generically as saxagliptin, is a work in progress. The new safety study of Onglyza followed nearly 16,500 patients with type 2 diabetes from 26 countries around the world. During the two-year study, investigators found that patients taking the diabetes drug experienced no greater risk for cardiovascular trouble than others, with all participants at known risk for heart attack.
Researchers found a small increase in hospitalizations for cardiovascular events, including heart attack, stroke, hospitalization for unstable angina, angioplasty, heart failure, or death. Among those who took the drug, 12.8 percent experienced heart problems, compared to 12.4 percent for those who did not.
Although considered by investigators as an insignificant difference, the “data also show an increase in hospitalization for heart failure in patients receiving saxagliptin, which was not expected and deserves further study,” Eugene Braunwald, a heart doctor at Brigham and Women’s and Harvard Medical School, said in a statement.
As researchers emphasize the imperative for further study, they’re quick to point out the benefits of the drug. “Patients who received saxagliptin also had better control of blood sugar levels and a reduced need for insulin therapy,” said Itamar Raz, of Hadassah Medical Center in Israel.
However, “our data also show an increase in hospitalization for heart failure in patients who received saxagliptin, which was not expected and deserves further study,” the study's chairman, Dr. Eugene Braunwald, of the cardiovascular division at Brigham and Women’s and Harvard Medical School, said in the hospital news release.
But the drug had real benefits, as well. “Patients who received saxagliptin also had better control of blood sugar levels and a reduced need for insulin therapy,” noted the study’s co-principal investigator, Dr. Itamar Raz, of Hadassah Medical Center. As another benefit, he said, the drug also prevented the progression of microalbuminuria, a form of kidney damage.
Source: Scirica BM, Bhatt DL, Braunwald E, Steg G, Davidson J. Saxagliptin And Cardiovascular Outcomes In Patients With Type 2 Diabetes Mellitus. New England Journal Of Medicine. 2013.