The SimpliciT1 Study: A Randomized, Double-Blind, Placebo-Controlled Phase 1b/2 Adaptive Study of TTP399, a Hepatoselective Glucokinase Activator, for Adjunctive Treatment of Type 1 Diabetes

<b>Objective</b> <p>Despite advances in exogenous insulin therapy, many patients with type 1 diabetes do not achieve acceptable glycemic control and remain at risk for ketosis and insulin-induced hypoglycemia. We conducted a randomized controlled trial to determine whether TTP399, a novel hepatoselective glucokinase activator, improved glycemic control in people with type 1 diabetes without increasing hypoglycemia or ketosis. </p> <p><b>Research design and methods</b></p> <p>SimpliciT1 was a Phase 1b/2 adaptive study. Phase 2 activities were conducted in 2 parts. Part 1 randomized 20 participants using continuous glucose monitors (CGM) and continuous subcutaneous insulin infusion (CSII). Part 2 randomized 85 participants on multiple daily injections of insulin or CSII. In both Part 1 and 2, participants were randomized to TTP399 800 mg or matched placebo (fully blinded) and treated for 12-weeks. The primary endpoint was the change in HbA1c from baseline to week 12.</p> <p><b>Results</b></p> <p>The difference in the change in HbA1c from baseline to week 12 between TTP399 and placebo was -0.7% (95% CI -1.3, -0.07) in Part 1 and -0.21 (95% CI -0.39, -0.04) in Part 2. Despite a greater decrease in HbA1c with TTP399, the frequency of severe or symptomatic hypoglycemia decreased by 40% relative to placebo in Part 2. In both Part 1 and Part 2, plasma beta-hydroxybutrate and urinary ketones were lower during treatment with TTP399 than placebo. </p> <p><b>Conclusions</b></p> <p>TTP399 lowers HbA1c and reduces hypoglycemia without increasing the risk of ketosis and should be further evaluated as an adjunctive therapy for the treatment of type 1 diabetes.</p>