Shortly after the FDA published its warning, the non-profit Institute for Safe Medication Practices (ISMP) released its own report on the evidence linking saxagliptin and other incretin mimetics to pancreatitis. The ISMP analyzed serious adverse events reported to the FDA Adverse Event Reporting System (FAERS) involving two incretin mimetics, exenatide (Byetta) and liraglutide (Victoza), and three DPP-4 inhibitors, saxagliptin (Onglyza, Kombiglyze), sitagliptin (Januvia), and linagliptin (Tradjenta).
Institute investigators compared the adverse reactions reported for these drugs to those reported for other antidiabetic medicines with different modes of action. Over a one year period, there were 1,732 reports filed for the five diabetes medicines, including 831 cases of pancreatitis and 105 cases of pancreatic cancer. It has been estimated that between one and 15 percent of adverse reactions are reported to FAERS, with six percent reported on average. There were 574 reports filed on the comparison drugs, with 18 instances of pancreatitis and two cases of pancreatic cancer reported. The ISMP report concluded: “These results add additional scientific weight to the association of all five GLP-1 agents with reports of pancreatitis.” The scientists also repeated the recommendations of the JAMA study authors, calling for “further investigation” of the drugs.
In 2014, a couple in Kentucky filed an Onglyza lawsuit alleging that several incretin mimetic class diabetes medications caused the plaintiffs to develop pancreatic cancer. In their Onglyza lawsuit, the couple claims they never would have taken the mimetic class diabetes medications had they, or their doctor, been warned about the risk of developing pancreatic cancer.
Does Onglyza Cause Thyroid Cancer?
At this point the little research available raises concerns but provides no clear answers.
On this question, it is important to remember that DPP-4-inhibitors and incretin mimetic drugs have different means of operation.
As explained above, DPP-4 inhibitors like Onglyza and Kombiglyze prevent the GLP-1 “key” from being broken. Incretin mimetics are like another key that fits the same pancreatic doors (receptors). Incretin mimetics are sometimes called GLP-1 receptor agonists (an agonist is a chemical that binds to a receptor and triggers a reaction). An excellent enlargeable illustration showing how incretin mimetics and DPP-4 inhibitors work is available on the website of Diabetes Care, a journal published by the American Diabetes Association.
The different modes of action of these two types of drugs may explain what has been found so far in terms of a link to thyroid cancer. A 2015 review of cancer risk associated with incretin mimetics and DPP-4 inhibitors, including Onglyza, reported that analyses of the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) have linked both types of drugs to a “significantly higher risk of pancreatic cancer.” But a higher risk of thyroid cancer was only associated with incretin mimetics (GLP-1 receptor agonists) not DPP inhibitors.
The above-mentioned investigation by the Institute for Safe Medication Practices found thyroid cancer was associated with two incretin mimetics: exenatide (Byetta) and liraglutide (Victoza). Byetta was linked with 14 cases of thyroid cancer, Victoza with 17 cases. In a separate ISMP Medication Safety Alert, the watchdog group stated their results were statistically significant for Byetta and Victoza compared to the control drugs. The two ISMP reports were in conflict regarding saxagliptin, with one report saying there was one case of thyroid cancer linked to saxagliptin and the other saying it was linked to another DPP-4 inhibitor, sitagliptin.
Does this mean there is no cause for concern with Onglyza? Unfortunately, no. As pointed out in a 2013 article in Diabetes Care, antidiabetic drugs have a history of being released with no long-term research showing benefits. Evidence of harm has been hidden or ignored and regulators have been slow to react. Drugs like Onglyza and the incretin mimetics are relatively new to the market and little is known about their long-term effects. Moreover, Onglyza operates on the same GLP-1 pathway as the incretin mimetics, which have been linked to thyroid cancer. Lastly, the research into DPP-4 inhibitors, incretin mimetics, and thyroid cancer was based on data in the FDA’s adverse reporting system. But only a small percentage of adverse events are reported to that system.
Patients taking Onglyza or Kombiglyze are advised to be on the alert for signs of thyroid cancer. Symptoms (from the Mayo Clinic) include
- A lump that can be felt through the skin on the neck
- A change in the voice
- Difficulty swallowing
- Pain in the neck and throat
- Swollen lymph nodes in the neck
If you have experienced any of these symptoms after taking Onglyza or Kombiglyze, contact a personal injury attorney at Baum, Hedlund, Aristei & Goldman today to learn more about filing an Onglyza lawsuit.