Janssen Pharmaceuticals’ type 2 diabetes medication is under new scrutiny. This new scrutiny follows confirmation from the Food and Drug Administration (FDA) that use of the drug canagliflozin, sold as Invokana and Invokamet, potentially increases the risk of amputation of the feet or legs. Most of these amputations have involved the toe and middle of the foot. Amputations of the leg, both above and below the knee, have also been necessary in some cases.
New Clinical Trials Show Dangers of Invokana
The FDA initially highlighted this alarming side effect last year following results from two clinical trials. These clinical trials indicated that Invokana and Invokamet XR potentially caused patients to be twice as likely to require an amputation than those who received a placebo. The initial trial, CANVAS, demonstrated that 5.9 of 1,000 patients taking Invokana had an amputation within a year. Meanwhile, the number of individuals who had amputations from those taking a placebo was 2.8 out of 1,000. A second trial, CANVAS-R, was conducted with similar results. Out of 1,000 people, 7.5 taking the drug had an amputation while the amount of those who received an amputation while on a placebo was 4.2.
On Tuesday, the FDA stated that these medications will now receive mandatory black box warnings. This is the strictest type of warning issued by the FDA, indicating significant health risks and detrimental side effects for patients. Janssen also announced that a majority of patients who had undergone amputations would likely require additional surgery. In response to the recent FDA studies, Janssen issued a statement saying, “Patient safety is our highest priority. We are working with the FDA to include this information in the prescribing information for canagliflozin and look forward to the presentation of the full CANVAS Program results at the American Diabetes Association Scientific Sessions in June.”
Other Side Effects Associated With Invokana
Aside from the correlation with amputations, the drug also has other negative effects. These negative side effects include decreased cardiovascular health and an increased chance of bone fractures and urinary tract infections. Researchers encourage doctors to look at pre-existing conditions that could be exacerbated when patients take the drug. The potentially exacerbated pre-existing conditions include peripheral vascular disease, neuropathy, diabetic foot ulcers, and previous amputations.
An announcement of this magnitude has many industry insiders wondering what this could mean for Invokana’s competitors. The competing drugs that fall into this specific class of diabetes treatments are known as sodium-glucose cotransporter 2 inhibitors. This class of diabetes drugs includes well-known names like Farxiga and Jardiance. Seamus Fernandez, an analyst at the healthcare-specialized investment bank Leerink Partners, has predicted that Jardiance in particular will benefit from the market losses that are projected for Invokana. Mr. Fernandez believes that many doctors will likely switch patients away from Invokana immediately.
Investors in Johnson & Johnson (J&J) are also wondering if they should be worried about this new research. Janssen is the pharmaceutical arm of the American multinational manufacturer. However, Fernandez believes that they do not have much cause for concern. He doubts that the class of drugs overall will suffer a substantial setback. Regardless, adding the FDA’s strongest safety warning to Invokana’s packaging will undoubtedly create issues for this J&J company.