According to the CANVAS study, out of 1,000 patients studied 5.9 of them had the higher risk of amputation as a result of taking Invokana. This stood in contrast to the 1,000 patients taking a placebo. Only 2.8 of patients taking the placebo had a high a risk of amputation.
A second study called the CANVAS-R, a study of the effects of Canagliflozin on Renal Endpoints in Adult Participants With Type 2 Diabetes Mellitus, was also conducted and confirmed the higher risk of amputation due to Invokana with its results as well. As a result the FDA has required the diabetes drug to carry it’s most severe label, known as the black box label, or Boxed Warning.