How safe and effective is non-insulin drug dapagliflozin long-term for patients with uncontrolled type 1 diabetes?

This study compared two doses of dapagliflozin (Farxiga) to a placebo to determine how effective and safe they were long-term for patients with uncontrolled type 1 diabetes (T1D). The results showed that both doses were able to reduce blood glucose levels and body weight but increased the risk of ketoacidosis.

Insulin is not effective enough to lower blood glucose levels in some patients with T1D. High blood glucose levels can lead to further complications and should be reduced using other types of drugs. Sodium-glucose cotransporter 2 inhibitors, such as dapagliflozin, are a class of drugs that may improve treatment results alongside insulin. Previous studies have shown that dapagliflozin is effective in the short-term for patients with uncontrolled T1D. It is unclear how effective it is long-term for these patients.

673 patients with uncontrolled T1D receiving insulin were divided into three groups. 231 patients received low dose (5 mg) dapagliflozin, 226 patients received high dose (10 mg) dapagliflozin and 216 received a placebo. Patients’ results were examined after 52 weeks.

HbA1c is a blood test used to examine average blood glucose levels over the previous three months. Low dose dapagliflozin reduced HbA1c by 0.2% more than the placebo. High dose dapagliflozin reduced HbA1c by 0.25% more than the placebo.

After 52 weeks, 35.3% of the low dose dapagliflozin group, 35.2% of the high dose dapagliflozin group and 22.3% of the placebo group had reduced their HbA1c levels by 0.5% or more. Patients were 1.85 times more likely to reduce their HbA1c levels by 0.5% or more without developing low blood glucose (hypoglycemia) with dapagliflozin than a placebo.

Patients in the low dose dapagliflozin group lost 4.42% more weight compared to the placebo group.  Patients in the high dose dapagliflozin group lost 4.86% more weight than the placebo group.

82.3% of the low dose dapagliflozin group, 75.9% of the high dose dapagliflozin group, and 75.4% of the placebo group reported side effects. The most common side effects were colds, chest infections, frequent urination, and headaches. 

4.1% of the low dose dapagliflozin group, 3.7% of the high dose dapagliflozin group, and 0.4% of the placebo group developed ketoacidosis (a serious side effect of uncontrolled diabetes). The number of patients that developed hypoglycemia was similar in all groups.

The authors concluded that dapagliflozin was safe and effective for patients with uncontrolled T1D. Symptoms of ketoacidosis should be monitored closely in patients receiving dapagliflozin.

The manufacturer of dapagliflozin, AstraZeneca, funded this study. The results of this study were limited by the fact that different patients were receiving different types and doses of insulin. Patients with other health problems were excluded from this study so these results may not apply to them.