vTv Therapeutics has randomised the first participant in its CATT1 Phase 3 trial, which is focused on evaluating cadisegliatin as an adjunctive treatment to insulin for adults with type 1 diabetes (T1D).
Cadisegliatin, also known as TTP399, acts as a liver-selective glucokinase activator and has received breakthrough therapy designation from the US Food and Drug Administration (FDA).
In the ongoing trial, vTv Therapeutics aims to enrol around 150 participants across up to 25 sites in the US.
The study is a double-blind, placebo-controlled trial investigating the efficacy and safety of cadisegliatin over six months. Participants will be evaluated under two dosage regimens and compared to those receiving a placebo.
All participants will use continuous glucose monitors to measure the primary endpoint, which is the incidence of level 2 and 3 hypoglycaemic events.
vTv Therapeutics chief medical officer Thomas Strack said: “Randomising the first participant in CATT1 represents another key milestone for vTv’s development of cadisegliatin as a potential therapy to improve glycemic control for the nearly 1.6 million Americans living with T1D.
“We look forward to reporting topline Phase 3 data from CATT1 in the second half of 2026.”
The FDA had previously lifted a clinical hold on the CATT1 trial in March 2025. This followed vTv Therapeutics’ clarification that an experimental artefact was responsible for a chromatographic signal found in a prior study of cadisegliatin.
The clinical hold was initially placed in July 2024 due to this discovery, although no patients had been dosed at that time.
According to vTv Therapeutics, the CATT1 trial will not collect additional safety data beyond six months, which allows the firm to obtain topline data more swiftly. Secondary endpoints include assessing reductions in haemoglobin A1C levels, time in target glycaemic range, and the incidence of diabetic ketoacidosis.
vTv Therapeutics is engaged in developing multiple small molecule drug candidates aimed at treating diabetes and other chronic diseases. While cadisegliatin has shown promise in early studies and has been well-tolerated among over 500 subjects, its safety and effectiveness are yet to be established for commercial use.
