Possible Kidney and Fracture Side Effects With Canagliflozin Use
In a review of nine phase II and phase III trials, FDA reviewers found that the SGLT2 inhibitor canagliflozin was less effective in a trial of patients with moderate renal impairment, a population already at risk for adverse effects involving the kidney. This is a significant concern since canagliflozin was associated with osmotic diuresis and volume depletion events, the reviewers said on January 8, prior to an FDA advisory meeting to consider whether to recommend approval of the diabetes drug. In addition to possibly having adverse effects on the kidneys, animal studies have shown increases in trabecular bone volume and decreased bone turnover with canagliflozin use, potentially related to carbohydrate malabsorption. These findings led reviewers to conclude that “longer data is required to assess the chronic effect of canagliflozin on bone mineral density.”
Potential Risks of Type 2 Diabetes Drugs
Canagliflozin, developed by pharmaceutical giant Johnson & Johnson, functions by inhibiting glucose reabsorption in the kidney so that sugar is excreted in the urine rather than reabsorbed into the blood stream. If canagliflozin is approved by the FDA, it will be the first SGLT2 inhibitor to enter the market. Last year, the agency denied approval of another SGLT2 inhibitor, dapagliflozin, largely due to concerns about bladder and breast cancer risks, asking Bristol-Myers Squibb and AstraZeneca for more data on the risks and benefits of the medication. One of the most popular type 2 diabetes drugs currently on the market, Actos (pioglitazone), has been found to possibly cause bladder cancer in patients when used for more than one year.
Canagliflozin Awaiting FDA Approval
Despite improvements in HDL cholesterol, weight and blood pressure with canagliflozin use, the medication appeared to raise LDL cholesterol, a “well established biomarker” of cardiovascular risk, the FDA reviewers noted. In addition, reviewers found an increase in total fractures and upper extremity fractures with the use of canagliflozin, although this wasn’t significant. The medication was also associated with an increased incidence of genital mycotic infections and urinary tract infections, FDA reviewers concluded. Johnson & Johnson filed a new drug application for canagliflozin in May 2012, and an approval decision is expected in March 2013. Although the FDA does not have to follow the advise of its advisory committees, it typically does.