This is a Phase 3 trial of cadisegliatin as adjunctive therapy to insulin in participants with Type 1 Diabetes Mellitus.

Study TTP399-302 is a 26-week, Phase 3 trial designed to measure the relative efficacy of adjunctive treatment with cadisegliatin to reduce the incidence of Level 2 or Level 3 hypoglycemia in participants with Type 1 Diabetes Mellitus compared to placebo (insulin alone) over 26 weeks of continuous therapy.

Inclusion Criteria:

• Individuals ≥18 years
• Diagnosed T1DM with a minimum of 3 years since diagnosis
• Has had at least 1 hypoglycemic event of Level 2 (glucose level <54 mg/dL or <3 mmol/L, [CGM or SMBG confirmed]) or Level 3 (defined as a severe hypoglycemia with altered mental state and/or physical status requiring assistance) in the last 2 months prior to Screening
• HbA1c value of <9.5% at Screening
• Is currently on CSII (closed-loop systems are prohibited) or is on MDI for at least 6 months prior to the Screening Visit and is willing to stay on same type of insulin treatment and the current mode of insulin administration (CSII or MDI injection treatments) for the duration of the study
• Must have been on a CGM device for at least 3 months prior to Screening

Exclusion Criteria:

• Has T2DM, monogenic diabetes, maturity-onset diabetes of the young, other unusual or rare forms of diabetes mellitus, or diabetes resulting from a secondary disease
• Has been hospitalized for DKA within 3 months prior to Screening
• Has uncontrolled hypothyroidism or hyperthyroidism
• History of eating disorder within the last 2 years such as anorexia, bulimia, diabulimia or neglecting to give insulin to manipulate weight
• Has an active or untreated malignancy, or has been in remission from malignancy for ≤5 years except well-treated basal cell or squamous cell skin cancer or cervical cancer in situ
• Has used any of the following medications within the specified time periods - any non-insulin anti-diabetic therapies, e.g., sodium glucose cotransporter-2 (SGLT-2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, metformin, sulfonylureas, dipeptidyl peptidase-4 (DPP-4) inhibitors, or pramlintide, alpha-glucosidase inhibitors, or glucose-dependent insulinotropic polypeptide agonists) or weight loss medications within 30 days prior to the Screening
• Has used a hybrid closed-loop system (e.g., Medtronic 670G, Omnipod 5, or Tandem X2 with control IQ) or Do-It-Yourself looping within the last 30 days prior to the Screening Visit, and agrees to not start hybrid closed-loop systems or Do-It-Yourself looping during the study.
• Has an estimated glomerular filtration rate (eGFR) <30 mL/min/1.73 m2 utilizing the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation at Screening
• Has uncontrolled hypertension prior to Screening