Researchers warn about gangrene cases in patients on SGLT2 diabetes drugs

After the FDA last year slapped a warning label on SGLT2 diabetes drugs, detailing risks of an infection with a rare flesh-eating bacteria, a team of researchers has come out with a new set of numbers—and a warning for doctors prescribing the drugs.

In a study published in the Annals of Internal Medicine, researchers found patients taking SGLT2 drugs—a class that includes Johnson & Johnson’s Invokana, AstraZeneca’s Farxiga, and Eli Lilly and Boehringer Ingelheim’s Jardiance —suffered from 55 unique cases of Fournier's gangrene, a rare flesh-eating bacterial infection of the genitals. The cases were recorded between March 1, 2013, and January 31, 2019.

The researchers collected those numbers from the FDA’s adverse event reporting database. Thirty-nine patients were men and 16 were women. 

The rare condition was associated with severe consequences. All patients had surgery to remove unhealthy tissue and were “severely ill.” Three patients died. Eight had fecal diversion surgery, while two others developed flesh-eating infections in lower extremities that required amputations.  

To set those numbers in a historical context, researchers looked at Fournier's cases between 1984 and January 31, 2019. The FDA tracked 19 cases during that time frame for patients on metformin, insulin glargine, short-acting insulin, Merck’s Januvia plus metformin, and Eli Lilly and Boehringer Ingelheim’s GLP-1 drug Trulicity. Two of those patients died.

In the Annals study, researchers note they can’t establish causality, and that there may be more cases that went unreported.

Still, they said Fournier's gangrene is a “newly identified safety concern” for patients on SGLT2 drugs and warned doctors prescribing the drugs to be “aware of this possible complication." They also wrote that doctors should “have a high index of suspicion to recognize it in its early stages.” 

The study comes as SGLT2 drugmakers are counting on those treatments for growth. Johnson & Johnson’s Invokana sales have been hit by an amputation warning unique in the class, but the drugmaker recently reported data in diabetes patients suffering chronic kidney disease it hopes can help right the course for the drug.

For their part, Lilly and Boehringer posted strong growth for Jardiance last year. Lilly reported that sales for the drug jumped 47% last year to $658 million. AZ’s Farxiga is also on the upswing, leaping 30% last year to $1.39 billion.