Further studies are required to define the role of TTP399 in the management of type 1 diabetes,” John Buse, MD, PhD, director of the Diabetes Center, director of the North Carolina Translational and Clinical Sciences Institute, executive associate dean for clinical research at the University of North Carolina School of Medicine in Chapel Hill and a principal investigator for the study, told Healio. “Whether it will provide for moderate benefits in all patients or big benefits in particular subgroups is an area of great interest to me. We are in the process of doing analyses to try to understand that better.”

Role of insulin

Researchers used two statistical approaches to evaluate the effects of 800 mg TTP399 in 85 adults. The primary statistical analysis evaluated the effect on HbA1c regardless of treatment adherence or notable changes in insulin administration. Under the primary statistical analysis, the trial achieved its primary objective by demonstrating improvements in HbA1c for TTP399 compared with placebo at week 12 (P = .03).

To eliminate the possibility that the reduction in HbA1c was driven by administration of excess insulin ( 3 U per day), researchers conducted a second estimand analysis. Based on this analysis, participants treated with TTP399 achieved a placebo-subtracted reduction in HbA1c of 0.32% (P = .001), according to the release. Participants assigned TTP399 experienced a mean 0.21% reduction in HbA1c; those assigned placebo experienced a 0.11% increase in HbA1c. Mean baseline HbA1c was 7.6% after the insulin optimization period.

Researchers said the drug was well tolerated, with no between-group differences in treatment-emergent adverse events overall or when stratified by system organ class. There was no diabetic ketoacidosis in either treatment group. There was no severe hypoglycemia in the treated group and one incident in the placebo group.

Improved glucose response

Participants assigned TTP399 experienced fewer symptomatic hypoglycemic episodes compared with those assigned placebo (2 vs. 8).

Daily time spent in the recommended glucose range improved by approximately 2 hours among participants who received TTP399 vs. placebo (P = .03). Those assigned TTP399 also reduced their total daily mealtime bolus insulin dose by a mean of 11% relative to baseline (P = .02), whereas participants assigned placebo experienced a mean 3% decrease relative to baseline.