LISBON – Despite some earlier concerns over safety, sodium-glucose cotransporter (SGLT) inhibitors appear to be back on track for adjunctive use in people with type 1 diabetes (T1DM), according to phase 3 study findings presented at the annual meeting of the European Association for the Study of Diabetes.
Results of the DEPICT-1 study, showed improved glycemic control, greater weight loss, and no increased risk for either hypoglycemia or ketoacidosis in people treated with the SGLT2 inhibitor dapagliflozin (Farxiga) versus those treated with placebo.
EASD/Susanne Wysocki
Dr. Paresh Dandona
When researchers compared the two dapagliflozin doses with placebo, the mean difference in body weight from baseline to week 24 was –2.96% and –3.72% (both P less than .0001).
Rates of any hypoglycemia in the placebo, 5-mg dapagliflozin, and 10-mg dapagliflozin groups were a respective 79.6%, 79.4%, and 79.4%, and rates of severe hypoglycemia were 7.3%, 7.6%, and 6.4%.
Diabetic ketoacidosis occurred in a respective 1.2%, 1.4%, and 1.7% of patients treated with placebo, dapagliflozin 5 mg, and dapagliflozin 10 mg, respectively.
“Based on this 24-week study, dapagliflozin may be considered as a good candidate as an adjunct to insulin to improve glycemic control in type 1 diabetes,” said the lead investigator for the DEPICT-1 trial, Paresh Dandona, MD, PhD, at the EASD 2017 meeting.
“There may also be other potential long-term cardiovascular and renal benefits, which have recently been demonstrated in type 2 diabetes,” suggested Dr. Dandona, who is a distinguished professor of medicine and chief of the division of endocrinology at the State University of New York at Buffalo. “Of course, that’s an open question, which needs to be investigated and determined in future.”
DEPICT-1 is the first phase 3, randomized, blinded, clinical trial of a selective SGLT2 inhibitor in T1DM, the study’s investigators said in an early online publication (Lancet Diabetes Endocrinol. 2017 Sep 13. doi: 10.1016/S2213-8587[17]30308-X). The study was conducted at 143 sites in 17 centers and involved 833 people with T1DM who were not achieving optimal blood glucose control.
Adults with an HbA1c of 7.7% or higher who had been taking insulin for at least 12 months were recruited and underwent an 8-week lead-in period to optimize their diabetes management before being randomized to take placebo or dapagliflozin 5 mg or 10 mg for 52 weeks. The primary endpoint was the change in HbA1c at Week 24.
DEPICT-1 “provides encouraging short-term data for the efficacy of adjunct SGLT2 inhibition in type 1 diabetes but might also provide insights into how the risk of ketoacidosis can be minimized,” John Petrie, MD, commented in an editorial that accompanied the published findings.
Dr. Petrie, professor of diabetic medicine at the Institute of Cardiovascular and Medical Sciences at the University of Glasgow, observed, however, that the results needed to be considered in the context of similar, and also recently presented, findings from the inTandem3 trial (N Engl J Med. 2017 Sep 13. doi: 10.1056/NEJMoa1708337) with the investigational dual SGLT1/SGLT2 inhibitor sotagliflozin. Other trials are expected to report soon with another SGLT2 inhibitor, empagliflozin.
In inTandem3, sotagliflozin helped more people who had T1DM and were on stable insulin to achieve an HbA1c level of 7% or lower at week 24 with no episodes of severe hypoglycemia or diabetic ketoacidosis, compared with those who took insulin alone (28.6% vs. 15.2%; P less than .001). However, the overall rates of ketoacidosis were higher in the patients treated with sotagliflozin than in those treated with placebo, at 3% versus 0.6%, respectively.
In both inTandem3 and DEPICT-1, strategies were in place to help carefully monitor and manage ketoacidosis. Dr. Petrie observed that patients in the latter trial were given a meter that measured both their blood glucose and ketones and were seen in a clinic regularly to assess the risk of ketoacidosis. These frequent visits, which occurred every 2 weeks, were shown to have an independent effect on HbA1c, he pointed out.
“Nevertheless, the investigators kept real-world clinical practice in mind by providing a very simple rule that insulin doses should be reduced by no more than 20% when study medication was started and that they should subsequently be titrated back towards the initial dose,” Dr. Petrie said. “This rule seemed to be quite effective in mitigating ketoacidosis and is feasible to implement in modern clinical practice since meters that measure ketones are increasingly available.
So does this mean a license for SGLT-targeting agents in T1DM could be coming soon? Not yet, Dr. Petrie suggests. “Regulators are likely to await at least the results of the 12-month follow-up, and data from other ongoing trials, before considering an indication for SGLT2 inhibitors in type 1 diabetes,” he said.
Adjunct treatment with these drugs also may require that individuals have “a good understanding of the early-warning symptoms of ketoacidosis” and be prepared to undertake regular home monitoring of both their blood glucose and ketones, as well as having a high level of communication with their diabetes health care providers.
AstraZeneca and Bristol-Myers Squibb funded the study.
Dr. Dandona received research support from AstraZeneca, Novo Nordisk, Boehringer Ingelheim, and AbbVie and was a consultant to AstraZeneca, Novo Nordisk, Sanofi-Aventis, and others.
Dr. Petrie disclosed receiving personal fees and travel expenses from Novo Nordisk; grants and personal fees from Sanofi-Aventis, Quintiles, and Janssen; nonfinancial support from Merck and Itamar Medical; and personal fees from Lilly, ACI Clinical, and Pfizer.