The FDA said it would not approve the novel diabetes drug dapagliflozin until drugmakers Bristol-Myers Squibb and AstraZeneca supply more data on the drug's benefits and risks. The two companies announced that they had received a complete response letter from the FDA, telling them the agency needs more data from ongoing trials, and possibly from new trials as well. The companies were seeking approval for the first-in-class drug as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes.
An FDA advisory committee recommended against approving the drug at a July meeting by a 9-6 vote, citing concern over potential breast and bladder cancer risks. Dapagliflozin is an inhibitor of sodium glucose cotransporter-2 (SGLT2) that increases renal glucose elimination -- thereby allowing more sugar to be excreted with urine, reducing the amount in circulation.
At the July meeting, advisory panel members all praised the companies for developing such an innovative drug that doesn't attempt to regulate insulin in the body like other diabetes treatments, but just simply flushes glucose from the body. A hepatologist at the meeting called the dapagliflozin "brilliant in its simplicity." But the drug seemed to raise the risk of breast and bladder cancers in the 11 phase III clinical trials conducted by Bristol-Myers Squibb and AstraZeneca. There were nine bladder cancers reported in the 5,478 patients on the drug compared with one case in 3,156 controls; and there have also been nine cases of breast cancer in 2,223 women on the drug compared with just one in 1,053 female controls.
One FDA reviewer estimated that women taking dapagliflozin had a fourfold increased risk of developing breast cancer compared with those not taking the drug, and male diabetics had five times the risk for developing bladder cancer compared with the control group. On the efficacy side, patients receiving dapagliflozin plus metformin achieved better glycemic control than those treated with metformin plus placebo. AstraZeneca and Bristol-Myers Squibb said in a statement that they "remain committed to dapagliflozin and its development."