By Christina Morales, Editor-in-Chief
Periscope News Group
July 18, 2018
In order to change a drug label, market a new dosage or strength of a drug, or change the way a drug is made, a pharmaceutical company must first submit a supplemental new drug application (sNDA) to the FDA. Johnson & Johnson, the makers of the type 2 diabetes drug Invokana (canagliflozin), recently submitted an sNDA application so that it’s label could add that Invokana reduces the risks of cardiovascular events in type II diabetes patients who are potentially at risk for cardiovascular (CV) disease. Invokana – along with its fixed-dose combinations Invokamet and Invokamet XR – is a sodium-glucose co-transporter-2 (SGLT2) inhibitor that is used for treating type 2 diabetes. Unfortunately, Invokana currently has a black box warning – the highest warning given by the FDA – for the increased risk of amputations. Do the benefits of reduced cardiovascular complications outweigh the high risk for amputations?
One of the struggles of having type 2 diabetes is the potential for amputation. Diabetes may cause nerve damage and poor circulation that can be exacerbated by uncontrolled blood sugar levels. When these complications set in and aren’t closely monitored by a medical professional, infections can occur without a patient’s knowledge causing gangrene that could eventually require an amputation. One theory as to how Invokana increases this risk is that while this medication decreases blood sugar and blood pressure, it may also cause the blood to thicken and therefore pool in the foot.
When the FDA followed up on two large clinical trials, CANVAS and CANVAS-R, they found that amputations occurred approximately twice as often in patients treated with canagliflozin as compared to patients who were given a placebo. Moreover, it was determined that one out of every 69 patients who take Invokana for five years will have a drug-related amputation. Most amputations involved the toes or middle foot, but others were reported to have amputations above the knee and even amputations that tragically took both lower limbs.
Conversely, the benefits of Invokana pertaining to heart issues has shown that CV death was lowered by 13% and that nonfatal strokes decreased by 10%. Invokana also appeared to reduce the risk for hospitalization due to heart failure (HHF).
While Invokana may decrease cardiovascular incidents, it is important to note that other type 2 diabetes medications are on the market that don’t pose the increased risk for amputations. Furthermore, in the first-quarter 2018, Invokana sales dropped 12.7% due to competitive pressure. If approved for the cardiovascular indication, it is predicted that drug’s sales should increase which brings up the question: is J&J is adding this benefit of reduced cardiovascular disease to their label to increase their stock value at the risk of patient health? While every medication has its risks and benefits, it’s critical for patients to fully educate themselves concerning the drugs that they’re putting their trust in to prevent further medical complications.