Cadisegliatin as Adjunctive Therapy to Insulin in Participants With Type 1 Diabetes Who Are Using Hybrid Closed Loop (HCL) Systems (Hybrid CATT1)

May 22, 2026 updated by: vTv Therapeutics

Hybrid CATT1: Hybrid Closed Loop Insulin Pumps With Cadisegliatin as Adjunctive Treatment in Patients With Type 1 Diabetes A Phase 2a Double Blind Randomized Cross-Over Study

TTP399-206 is a Phase 2a multicenter double blind cross over randomized study of cadisegliatin in participants with T1D using hybrid closed loop systems to manager their diabetes. Patients using a hybrid closed loop insulin pump to manage their diabetes will be randomized to either receive blinded cadisegliatin 800 mg QD as an adjunctive therapy to their insulin treatment or placebo QD along with their insulin treatment. The trial begins with a screening period of up to 2 weeks, followed by a device training and insulin adjustment period of 1-2 weeks leading into the first double-blind treatment period of 6 weeks. There will then be a washout period of 1-2 weeks followed by the second double-blind treatment period of 6 weeks where the patient will cross-over to the treatment arm that they did not receive in the first treatment period.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

TTP399-206 is a 20 week, Phase 2a trial designed to evaluate efficacy and safety of cadisegliatin in participants with T1D who are using hybrid closed loop (HCL) systems to manage their condition to gather preliminary data to understand how cadisegliatin performs in an HCL setting.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Georgia
      • Atlanta, Georgia, United States, 30318
        • Atlanta Diabetes Associates
        • Principal Investigator:
          • Bruce W Bode, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Participants >= 18 years of age
  • Fasting plasma C-peptide levels <0.6 ng/ml
  • Average TIR < 70% at the end of the screening period
  • Currently on a hybrid closed loop device for at least 3 months and willing to stay on the same model of pump device for study duration
  • Willing to wear a study provided CGM for study duration
  • Capable of participating in a 30-minute lasting exercise test

Key Exclusion Criteria:

  • Have Type 2 Diabetes Mellitus (DM), monogenic diabetes, maturity-onset diabetes, other unusual or rare forms of DM, or diabetes resulting from a secondary disease.
  • Have been hospitalized for DKA within 3 months
  • Have uncontrolled hypothyroidism or hyperthyroidism
  • Have QTcF interval > 450 msec for males or > 470 msec for females
  • Have a personal or family history of long QT syndrome, Torsades de pointes, or other complex ventricular arrhythmias
  • Have persistent, uncontrolled hypertension
  • Have clinically significant cardiovascular or cerebrovascular disease
  • Have proliferative retinopathy or maculopathy requiring acute treatment
  • Have a serious concomitant systemic disorder incliuding but not limited to HIV or active Hep B or Hep C
  • Diagnosed and/or treated for malignancy within 3 years
  • Have used any of the following medications within the specified time periods: any non-insulin anti-diabetic therapies (e.g.SGLT-2 inhibitors, GLP-1 receptor agonists, metformin, sulfonylureas, DPP-4 inhibitors, pramlintide, a-glucosidase inhibitors, or glucose dependent insulinotropic polypeptide agonists) within 30 days, antipsychotic medications (e.g. olanzapine, risperidone, clozapine, quetiapine, and haloperidol) within 30 days, systemic corticosteroids for ≥7 days for a temporary medical condition within 30 days,

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Cadisegliatin 800 mg QD: Double Blind, Randomized Crossover Trial Design
If a patient is randomized to receive cadisegliatin 800 mg QD as an adjunctive therapy to their insulin treatment in the first double-blind treatment period of 6 weeks, there will then be a washout period of 1-2 weeks followed by the second double-blind treatment period of 6 weeks where the patient will cross-over to the placebo QD along with their insulin treatment arm
Drug: Cadisegliatin 800 mg QD
Cadisegliatin is an orally bioavailable small-molecule glucokinase activator, adjunctive therapy to insulin
Other Names:
  • TTP399
Placebo Comparator: Placebo: Double Blind, Randomized Crossover Trial Design
If a patient is randomized to receive placebo QD along with their insulin treatment in the first double-blind treatment period of 6 weeks, there will then be a washout period of 1-2 weeks followed by the second double-blind treatment period of 6 weeks where the patient will cross-over to the cadisegliatin 800 mg QD as an adjunctive therapy to their insulin treatment arm
Drug: Placebo
Placebo (insulin alone)

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
To assess the change in Time in Range (TIR)
Time Frame: last 2 weeks of the two 6-week treatment periods
Time in Range (TIR) based on study CGM in participants with T1D who are using hybrid closed loop systems on cadisegliatin vs placebo
last 2 weeks of the two 6-week treatment periods

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
CGM-based metric for glycemic control
Time Frame: last 2 weeks of the two 6-week treatment periods
Time In Tight Range (TITR)
last 2 weeks of the two 6-week treatment periods
CGM-based metric for glycemic control
Time Frame: last 2 weeks of the two 6-week treatment periods
Time Above Range (TAR)
last 2 weeks of the two 6-week treatment periods
CGM-based metric for glycemic control
Time Frame: last 2 weeks of the two 6-week treatment periods
Time Below Range (TBR)
last 2 weeks of the two 6-week treatment periods
CGM-based metric for glycemic control
Time Frame: last 2 weeks of the two 6-week treatment periods
Glucose Management Indicator (GMI)
last 2 weeks of the two 6-week treatment periods
CGM-based metric for glycemic control
Time Frame: last 2 weeks of the two 6-week treatment periods
Glucose variability (GV)
last 2 weeks of the two 6-week treatment periods
CGM-based metric for glycemic control
Time Frame: last 2 weeks of the two 6-week treatment periods
Time in Range (TIR) > 70%
last 2 weeks of the two 6-week treatment periods
Change in glucose control after standardized mixed meal tolerance test (MMTT)
Time Frame: 12 weeks
Glucose Peak Plasma Concentration (Cmax) based on study CGM after standardized mixed meal tolerance test (MMTT)
12 weeks
Change in glucose control after standardized mixed meal tolerance test (MMTT)
Time Frame: 12 weeks
Glucose Area under the plasma concentration versus time curve (AUC) based on study CGM after standardized mixed meal tolerance test (MMTT)
12 weeks
Change in glucose control after a standardized exercise test
Time Frame: 12 weeks
Glucose Peak Plasma Concentration (Cmax) based on study CGM after a standardized exercise test
12 weeks
Change in glucose control after a standardized exercise test
Time Frame: 12 weeks
Glucose Minimum Plasma Concentration (Cmin) based on study CGM after a standardized exercise test
12 weeks
Change in glucose control after a standardized exercise test
Time Frame: 12 weeks
Glucose Area under the plasma concentration versus time curve (AUC) based on study CGM after a standardized exercise test
12 weeks
To assess the change in Level 1, Level 2 , and Level 3 hypoglycemic incidence
Time Frame: 12 weeks
Number of events of Level 1, Level 2, and Level 3 hypoglycemia as determined by CGM and adjudicated level 3 hypoglycemic events per patient year in participants with T1D who are using hybrid closed loop systems on cadisegliatin vs placebo
12 weeks
Assess incidence of Serious Adverse Events (SAEs)
Time Frame: 14 weeks
Number of Serious Adverse Events (SAEs)
14 weeks
Assess incidence of Treatment Emergent Adverse Events (TEAEs)
Time Frame: 14 weeks
Number of treatment emergent adverse events (TEAEs)
14 weeks
Assess incidence of Treatment Emergent Adverse Events (TEAEs) leading to discontinuation
Time Frame: 14 weeks
Number of treatment emergent adverse events (TEAEs) leading to discontinuation of study drug
14 weeks
Assess incidence of Adverse Events of Special Interest (AESIs)
Time Frame: 14 weeks
Number of adverse events of special interest (AESIs)
14 weeks
Change from baseline in average daily total insulin dose
Time Frame: last week of the two 6-week treatment periods
Change from baseline in average daily total insulin dose in units (IU) based on manual entry in eDiary records from participants with T1D who are using hybrid closed loop systems on cadisegliatin vs placebo
last week of the two 6-week treatment periods

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
vTv Therapeutics

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Thomas Strack, MD, vTv Therapeutics LLC

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 1, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 15, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 22, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 1, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 1, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 22, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • TTP399-206

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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