Cadisegliatin as Adjunctive Therapy to Insulin in Participants With Type 1 Diabetes (CATT1)

July 24, 2026 updated by: vTv Therapeutics

Cadisegliatin as Adjunctive Therapy in Type 1 Diabetes: A 26-Week Double-Blind, Randomized, Placebo-Controlled Phase 3 Study

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

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not 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

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.

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.
150

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 3

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

  • Puerto Rico
      • San Juan, Puerto Rico, 00907
        • Solace Clinical Research
  • United States
    • Arizona
      • Scottsdale, Arizona, United States, 85260
        • Scottsdale Clinical Trials
    • Arkansas
      • Little Rock, Arkansas, United States, 72205
        • Baptist Health Center for Clinical Research
    • California
      • Granada Hills, California, United States, 91344
        • Amicis Research Center
      • Huntington Beach, California, United States, 92647
        • AME Clinical Research
      • Inglewood, California, United States, 90301
        • 310 Clinical Research
      • La Jolla, California, United States, 92037
        • Scripps Whittier Diabetes Institute
      • La Palma, California, United States, 90623
        • IMAX Clinical Trials
      • Modesto, California, United States, 95355
        • Paradigm Clinical Research - Modesto
      • San Diego, California, United States, 92120
        • Acclaim Clinical Research
      • San Diego, California, United States, 92108
        • Paradigm Clinical Research Centers LLC
      • Torrance, California, United States, 90502
        • The Lundquist Institute
      • West Hills, California, United States, 91307
        • Focus Clinical Research
    • Colorado
      • Englewood, Colorado, United States, 80113
        • Denver Endocrinology Diabetes and Thyroid Center
    • Florida
      • Clearwater, Florida, United States, 33756
        • BayCare Health Systems
      • West Palm Beach, Florida, United States, 33413
        • Metabolic Research Institute, Inc
    • Georgia
      • Atlanta, Georgia, United States, 30318
        • Atlanta Diabetes Associates
      • Columbus, Georgia, United States, 31904
        • Centricity Research - Columbus
      • Macon, Georgia, United States, 31210
        • The Jones Center Clinical Research, LLC
    • Idaho
      • Boise, Idaho, United States, 83709
        • Paradigm Clinical Research
    • Indiana
      • Indianapolis, Indiana, United States, 46254
        • DM Clinical Research
    • Iowa
      • Ames, Iowa, United States, 50010
        • Accellacare - McFarland
      • West Des Moines, Iowa, United States, 50265
        • Iowa Diabetes and Endocrinology Research Center
    • Kansas
      • Lenexa, Kansas, United States, 66219
        • Johnson County Clin-Trials, LLC
    • Maryland
      • Baltimore, Maryland, United States, 21239
        • MedStar Good Samaritan Hospital
    • Massachusetts
      • Boston, Massachusetts, United States, 02114
        • Massachusetts General Hospital Diabetes Research Center
    • Michigan
      • Farmington Hills, Michigan, United States, 48334
        • Profound Research LLC
    • Nevada
      • Las Vegas, Nevada, United States, 89128
        • Palm Research Center
      • Las Vegas, Nevada, United States, 89109
        • Excel Clinical Research
      • Reno, Nevada, United States, 89511
        • Vector Clinical Trials
    • New York
      • Albany, New York, United States, 12203
        • AMC Community Endocrinology
      • The Bronx, New York, United States, 10461
        • Jacobi Medical Center
    • North Carolina
      • Chapel Hill, North Carolina, United States, 27514
        • University of North Carolina at Chapel Hill
      • Charlotte, North Carolina, United States, 28210
        • Javarra Inc.
      • Greenville, North Carolina, United States, 27834
        • Physician's East PA
      • Morehead City, North Carolina, United States, 28557
        • Centricity Research Morehead City Multispecialty
    • Ohio
      • Canton, Ohio, United States, 44718
        • Diabetes & Endocrinology Associates of Stark County, Inc
      • Concord, Ohio, United States, 94520
        • John Muir Physician Network Clinical Research Center
    • Oregon
      • Medford, Oregon, United States, 97504
        • Velocity Clinical Research
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • University of Pennsylvania Perelman Center for Advanced Medicine
    • South Dakota
      • Sioux Falls, South Dakota, United States, 57104
        • Circle Clinical Research
    • Texas
      • Austin, Texas, United States, 78731
        • Texas Diabetes and Endocrinology, P.A
      • Dallas, Texas, United States, 75230
        • Velocity Clinical Research - Dallas
      • McKinney, Texas, United States, 75069
        • Tekton Research, LLC
      • Mesquite, Texas, United States, 75149
        • Southern Endocrinology Associates PA
      • Mesquite, Texas, United States, 75149
        • SMS Clinical Research LLC
      • San Antonio, Texas, United States, 78229
        • Diabetes & Glandular Disease Clinic, P.A.
      • Shavano Park, Texas, United States, 78231
        • Consano Clinical Research
    • Utah
      • Salt Lake City, Utah, United States, 84107
        • Wasatch Clinical Research, LLC
    • Washington
      • Seattle, Washington, United States, 98109
        • University of Washington Diabetes Institute
      • Spokane, Washington, United States, 99202
        • Citta Clinical Research, LLC
      • Spokane, Washington, United States, 99218
        • Velocity Clinical Research - Spokane

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

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

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: Parallel 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: 26 Week Double Blind Treatment Period - 800 mg QD
The main study uses a randomized, double-blind, placebo-controlled design with parallel assignment among 3 treatment arms. The trial begins with a screening period of up to 14 days, followed by a 28-day device training and insulin adjustment period leading into a 28-day baseline period before entering the 26-week treatment period. Insulin is adjunctive therapy.
Drug: Cadisegliatin 800 mg QD
Cadisegliatin is an orally bioavailable small-molecule glucokinase activator; adjunctive therapy to insulin.
Other Names:
  • TTP399
Experimental: Cadisegliatin: 26 Week Double Blind Treatment Period - 800 mg BID
The main study uses a randomized, double-blind, placebo-controlled design with parallel assignment among 3 treatment arms. The trial begins with a screening period of up to 14 days, followed by a 28-day device training and insulin adjustment period leading into a 28-day baseline period before entering the 26-week treatment period. Insulin is adjunctive therapy.
Drug: Cadisegliatin 800 mg BID
Cadisegliatin is an orally bioavailable small-molecule glucokinase activator; adjunctive therapy to insulin.
Other Names:
  • TTP399
Placebo Comparator: Placebo: 26 Week Double Blind Treatment Period
The main study uses a randomized, double-blind, placebo-controlled design with parallel assignment among 3 treatment arms. The trial begins with a screening period of up to 14 days, followed by a 28-day device training and insulin adjustment period leading into a 28-day baseline period before entering the 26-week treatment period. Insulin is adjunctive therapy.
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
Change in incidence of Level 2 or Level 3 hypoglycemia
Time Frame: 26 weeks
Number of events of Level 2 or Level 3 hypoglycemia in participants on cadisegliatin vs placebo.
26 weeks

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
To assess the change in HbA1c
Time Frame: 26 weeks
Change from baseline in HbA1c in participants on cadisegliatin vs placebo.
26 weeks
To assess the effects of treatment on the incidence of diabetic ketoacidosis
Time Frame: 26 weeks
Number of events of diabetic ketoacidosis participants on cadisegliatin vs placebo
26 weeks
To assess the effects of treatment on body weight
Time Frame: 26 weeks
Change from baseline in mean body weight
26 weeks
To assess the effects of treatment on CGM-based metrics for glycemic control
Time Frame: 26 weeks
Change from baseline for time in, above or below target range of participants on cadisegliatin vs placebo
26 weeks
To assess the effects of treatment on insulin dosing
Time Frame: 18 weeks
Change from baseline in average daily total insulin on cadisegliatin vs placebo
18 weeks
To assess the incidence of treatment emergent adverse events
Time Frame: 26 weeks
Number of treatment emergent adverse events with cadisegliatin vs placebo
26 weeks
To assess the incidence of treatment emergent adverse events leading to discontinuation
Time Frame: 26 weeks
Number of treatment emergent adverse events leading to discontinuation with cadisegliatin vs placebo
26 weeks
To assess the incidence of adverse events of special interest
Time Frame: 26 weeks
Number of adverse events of special interests with cadisegliatin vs placebo
26 weeks

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in incidence of Level 2 or Level 3 hypoglycemia
Time Frame: 52 weeks
Number of events of Level 2 or Level 3 hypoglycemia in participants on cadisegliatin vs placebo.
52 weeks
To assess the change in HbA1c
Time Frame: 52 weeks
Change from baseline in HbA1c in participants on cadisegliatin vs placebo
52 weeks
To assess the effects of treatment on CGM-based metrics for glycemic control
Time Frame: 52 weeks
To evaluate the change from baseline for time in, above or below target range of participants on cadisegliatin vs placebo
52 weeks
To assess the incidence of adverse events
Time Frame: 52 weeks
Evaluation and comparison of the number of adverse events with cadisegliatin vs placebo during the study
52 weeks
To assess the effects of treatment on the incidence of diabetic ketoacidosis
Time Frame: 52 weeks
Percentage of participants with incidence of diabetic ketoacidosis on cadisegliatin vs placebo
52 weeks
To assess the effects of treatment on insulin dosing
Time Frame: 52 weeks
Change from baseline in basal, bolus and total insulin dosing
52 weeks
To assess the effects of treatment on body weight
Time Frame: 52 weeks
Change from baseline in mean body weight
52 weeks
High sensitivity C-reactive protein
Time Frame: 26 and 52 weeks
Change from baseline of biomarkers
26 and 52 weeks
N-terminal pro brain [or B-type] natriuretic peptide
Time Frame: 26 and 52 weeks
Change from baseline of biomarkers
26 and 52 weeks
Urinary albumin excretion ratio
Time Frame: 26 and 52 weeks
Change from baseline of biomarkers
26 and 52 weeks
Estimated glomerular filtration rate
Time Frame: 26 and 52 weeks
Change from baseline of biomarkers
26 and 52 weeks
8-item Diabetes Distress Scale (participant and partner or family member)
Time Frame: 26 and 52 weeks
Change from baseline in PRO scores to assess the burden of hypoglycemia
26 and 52 weeks
Hypoglycemia Confidence Scale for participant and partner or family member
Time Frame: 26 and 52 weeks
Change from baseline in PRO scores to assess the burden of hypoglycemia
26 and 52 weeks
11-item/Short Form Hypoglycemia Fear Scale
Time Frame: 26 and 52 weeks
Change from baseline in PRO scores to assess the burden of hypoglycemia
26 and 52 weeks
Gold hypoglycemia awareness score
Time Frame: 26 and 52 weeks
Change from baseline in patient reported outcomes scores to assess the burden of hypoglycemia. Scale from 1 (always aware) to 7 (never aware).
26 and 52 weeks
Item 7 of Clarke hypoglycemia awareness scale
Time Frame: 26 and 52 weeks
Change from baseline in patient reported outcomes scores to assess the burden of hypoglycemia. Scale from less than 40 mg/dL to 79mg/dL.
26 and 52 weeks
Snyder's 1-item quality of sleep questionnaire
Time Frame: 26 and 52 weeks
Change from baseline in patient reported outcomes scores to assess the burden of hypoglycemia. Scale from 0 (terrible) to 10 (excellent).
26 and 52 weeks
World Health Organization-5 Well-Being Index
Time Frame: 26 and 52 weeks
Change from baseline in patient reported outcomes scores to assess the burden of hypoglycemia. Ranges from not confident to very confident.
26 and 52 weeks

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

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

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 (Actual)

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.
June 14, 2024

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).
March 13, 2024

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.
March 20, 2024

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.
March 27, 2024

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.
July 28, 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.
July 24, 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.
July 1, 2026

More Information

Terms related to this study

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.
  • TTP399-302

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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