The Two Dominant Classes of Diabetes Drugs Are under Recent FDA WarningsSep 11, 2015
The Centers for Disease Control and Prevention (CDC) calculates that 29.1 million Americans (9.3 percent of the population) have diabetes, creating a major market for treatments to control blood sugar. If left untreated, diabetes can result in serious long-term health consequences including blindness, nerve and kidney damage, and heart disease, according to the Food and Drug Administration (FDA).
The two major classes of type 2 diabetes drugs—DPP-4 inhibitors (Januvia, Onglyza) and SGLT-2 inhibitors (Invokana, Farxiga)—are under serious warnings from the Food and Drug Administration (FDA) for their side effects, the Motley Fool reports.
Oral DPP-4 inhibitors work by increasing incretin levels in the pancreas, which in turn inhibit the release of glucagon, which is responsible for pushing up blood sugar levels. The best-known DPP-4 inhibitor is Merck's Januvia, which is currently on pace to generate about $6 billion in sales in 2015, according to Motley Fool.
The slightly newer class of SGLT-2 inhibitors works by blocking the absorption of glucose in the kidneys and allowing a type 2 diabetic to excrete excess glucose through urine. The best-known SGLT-2 inhibitors are Johnson & Johnson's Invokana, Eli Lilly and Boehringer Ingelheim's Jardiance, and AstraZeneca 's Farxiga.
In May the FDA issued a safety announcement for patients taking SGLT-2 inhibitors warning that they could be at greater risk of ketoacidosis, a condition where high levels of acids build up in the blood. Ketoacidosis often results in hospitalization, Motley Fool reports. From March 2013 through June 6, 2014, the FDA says 20 instances of acidosis were reported in patients taking SGLT-2 inhibitors, with more cases suspected since then. Though the FDA has not advised patients to stop taking SGLT-2 inhibitors, the agency is further examining the safety of SGLT-2 inhibitors, and could require a warning label update in the future.
At the end of August, the FDA said that DPP-4 inhibitors had been linked to instances of severe, sometimes disabling, joint pain. Between Oct. 16, 2006 and Dec. 31, 2013, the FDA identified 33 instances of such joint pain, and 28 of these were in patients taking Januvia, according to Motley Fool. As with the SGLT-2 inhibitors, the FDA did not recommend that type 2 diabetics stop taking the DPP-4 inhibitor, but the FDA did encourage physicians to monitor patients for joint pain potentially tied to Januvia and other DPP-4 inhibitors. Januvia has also been linked to pancreatitis, an inflammation of the pancreas that can be extremely painful and sometimes fatal.
Diabetes is one of the leading causes of death in the United States. The CDC notes that a patients' risk of death jumps by 50 percent if they have diabetes. The condition is also costly, with significant annual expenses for medication and blood-testing supplies and regular screenings for complications. The CDC estimates that these direct costs, combined with costs such as lost wages, amount to $245 billion per year. DPP-4 inhibitors and SGLT-2 inhibitors are competing for the top place in the market and the FDA warnings highlight significant concerns about each drug class's safety.