A new study suggests that dipeptidyl peptidase (DPT-4) inhibitors, a class of Type 2 diabetes drugs that includes Onglyza and Kombiglyze XR, are not associated with a reduced risk of death, unlike some other new diabetes treatments.
The author of the study, which was published this week in the Journal of the American Medical Association, analyzed 36 trials involving 176,310 patients who were treated with DPT-4 inhibitors, sodium-glucose cotransporter (SGLT-2) inhibitors (such as Jardiance), and glucagon-like peptide (GLP-1) agonists (Victoza, Byetta, etc.)
While all of the medications lowered blood sugar levels, only SGLT2 inhibitors and GLP-1 agonists appeared to reduce the likelihood of death.
SGLT-2 inhibitors were associated with a 20% reduction in overall mortality risk compared to a placebo. The were also shown to reduce the risk of death due to a cardiovascular event, such heart attack or stroke, by 21%
Medications in the GLP-1 agonist class reduced the overall death risk by 18% compared to a placebo nd lessened the risk of cardiovascular death by 15%.
While the study did not suggest that any of the drugs caused harm, Onglyza and other DPT-4 inhibitors were not associated with any reduced risk of mortality.
“Patients with type 2 diabetes are at higher risk of dying from heart attacks or strokes, so we wanted to investigate which of these three treatments are most efficient at preventing death and cardiovascular diseases,” the study’s lead author, Dr. Sean Zheng of the National Heart and Lung Institute at the Imperial College of London, said in a press release announcing the study’s findings.
“Our hope is that in the crowded market that is diabetes medications, patients and their doctors have the necessary information to allow them to make informed decisions about long-term treatment strategies.”
Onglyza (saxagliptin) was approved by the U.S. Food & Drug Administration (FDA) in 2009, while Kombiglyze XR (metformin and saxagliptin) was approved the following year.
DPP-4 is an enzyme that breaks down GLP-1, an incretin hormone that stimulates the body to release insulin in response to a meal.
Type 2 diabetics secrete less GLP-1 than normal, which causes the pancreas to release inadequate amounts of insulin. By inhibiting DPP-4, saxagliptin allows GLP-1 to remain in the body longer, which causes the pancreas to produce more insulin.
The U.S. Food & Drug Administration (FDA) ordered new heart failure warnings for the labels of Onglyza and other saxagliptin-containing drugs in April 2016, after clinical trial data linked saxagliptin to a 27% increased risk of heart failure. The study also suggested that saxagliptin was associated with a higher risk of all-cause mortality.
Shortly after the FDA acted, plaintiffs around the country began to file Onglyza and Kombiglyze XR lawsuits accusing AstraZeneca and Bristol-Myers Squibb of concealing the cardiovascular side effects allegedly associated with saxagliptin, including heart failure, congestive heart failure, cardiac failure, and death
Earlier this year, all such federal claims were centralized before a single judge in the U.S. District Court, Eastern District of Kentucky. At least 98 lawsuits involving Onglyza and Kombiglyze XR are currently pending in that proceeding.