Sotagliflozin shows significant HbA1c reduction in type 1 diabetes

Lexicon Pharmaceuticals has announced successful results from its second Phase III clinical trial of the drug sotagliflozin in type 1 diabetes.
Sotagliflozin is a dual inhibitor of sodium-glucose co-transporter types 1 and 2 (SGLT1 and SGLT2). SGLT1 serves as a transporter for absorption of glucose and galactose in the gut, while SGLT2 is responsible for glucose reabsorption by the kidney.
Phase II studies of sotagliflozin have shown improvement in glucose control and reduction of mealtime insulin in people with type 1 diabetes.
In this Phase III study known as inTandem2, sotagliflozin has demonstrated a statistically significant reduction of HbA1c in adults with type 1 diabetes and a low risk of hypoglycemia. Ketoacidosis occurrence was, however, more likely to occur on sotagliflozin.
The inTandem2 study evaluated 782 adults with type 1 diabetes on insulin pump or multiple daily injection who were treated with either 200 mg of sotagliflozin once daily, 400 mg of sotagliflozin once daily, or a placebo.
Prior to starting them on sotagliflozi, insulin was optimised for all participants over a six-week period and all of them were maintained on optimised insulin during the whole study.
Upon entering the study, participants had an HbA1c between 53 mmol/mol (7%) and 97 mmol/mol (11%). After insulin optimisatio, just before the study period started, the mean HbA1c levels were 62 mmol/mol for those receiving a placebo, and 61 mmol/mol for both the 200mg and the 400mg sotagliflozin groups.
The primary goal of the study was to lower their HbA1c after 24 weeks of treatment with sotagliflozin.
At week 24, results showed a mean HbA1c improvement of 4 mmol/mol in both treatment arms compared with the placebo group.
Few serious adverse events were reported throughout the study and the incidence of severe hypoglycemia was 3.8% and 2.3% in the 200mg and 400mg groups, respectively.
No ketoacidosis occurred in those taking a placebo, one event of ketoacidosis occurred in the 200mg (0.4% of participants affected) and three events (1.1% of participants) occurred in the 400mg dose group.
As ketoacidosis is a dangerous short-term complication, this does present some cause for concern that will need to be monitored in future trials.
Another Phase 3 clinical trial, inTandem3, which includes 1,400 patients treated with sotagliflozin 400mg once daily without prior insulin optimisatio, is underway.