Single Arm Intervention Trial of DEKA TWIIST TM Insulin Pump Utilizing Tidepool Loop Algorithm in Pregnant People With Pre-existing Type 1 Diabetes

Suboptimal glycemic control during pregnancy contributes to adverse maternal and fetal health outcomes and previous automated insulin delivery (AID) studies have demonstrated improvement in glucose control across all ages and sexes irrespective of past treatment modality or diabetes duration with no increase in hypoglycemia. However, very few studies evaluating AID system use in pregnancy have been performed in the US and no AID systems are currently approved for use during pregnancy. The objective of this trial is to evaluate the safety and efficacy of THE TWIIST™ system that enables the selection of pregnancy-specific glucose targets. This phase 3 pivotal trial will assess the system's performance in pregnant people with pre-existing type 1 diabetes in the US, starting as early as pregnancy confirmation, continuing throughout the pregnancy including delivery and up to 6 weeks post-partum.

Study Overview

• Status: Not yet recruiting
• Conditions: Type 1 Diabetes; Pregnancy
• Intervention / Treatment: Device: Automated Insulin Delivery (AID)

• Study Type: Interventional
• Enrollment (Estimated): 32
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Chloe Miller, BS; Phone Number: 507-255-0316; Email: miller.Chloe4@mayo.edu

Study Locations

• United States
  • California
    • Stanford, California, United States, 94305
      • Stanford University
      • Contact: Rayhan Lal, MD; Phone Number: 8139758690; Email: ppwt1d@jaeb.org
  • Colorado
    • Aurora, Colorado, United States, 80045
      • University of Colorado, Anschutz Medical Campus
      • Contact: Sarit Polsky, MC; Phone Number: 8139758690; Email: ppwt1d@jaeb.org
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Mayo Clinic
  • New York
    • New York, New York, United States, 10029
      • Icahn School of Medicine at Mount Sinai
      • Contact: Carol Levy, MD; Phone Number: 8139758690; Email: ppwt1d@jaeb.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Singleton pregnancy is confirmed by ultrasound.
• Pregnant woman between pregnancy confirmation to 96/7 weeks gestation.
• Clinical diagnosis of T1D for 1 year or longer.
• Using insulin pump (AID/SAP) or multiple daily insulin injections at screening visit.
• Willing to use U100 aspart (Novolog) or lispro (Humalog) insulin during the study.
• Willing to announce all carbohydrate intake unless for the treatment or prevention of hypoglycemia.
• No significant maternal and/or fetal complications at the time of enrollment visit.
• Willing to abide by study protocol.
• Willing to learn and use study-provided devices and perform necessary actions for interacting with devices when needed.
• Able and willing to receive routine and specialty obstetric care during the study.
• Able to speak and understand English and provide informed consent.
• Able to have at least one care partner available during the study. A care partner is defined as an adult person (≥18 yrs.) who will either be staying in the same location as the participant or within a 40-mile radius and willing to be trained on study devices and using the TWIIST smartphone App (follower app), will to provide treatment of hypo- and hyperglycemia, and able to take the participant to the hospital or call 911 (emergency services) in case of an emergency.

Exclusion Criteria:

• Individuals with T2D, gestational diabetes, or other types of diabetes (e.g., CFRD, MODY, etc.).
• Use of basal insulin alone.
• Use of short-acting insulin alone, unless use is through an insulin pump.
• Severe allergy to medical grade adhesives within the last 3 months that would inhibit participant ability to wear the study devices.
• Significant maternal and/or fetal complications, such as pre-existing heart disease (untreated or unstable cardiac diseases), pre-existing severe kidney (eGFR < 45) disease and any other condition that limits participant safety as per investigator discretion.
• Unwilling to wear the study insulin pump for the duration of the study or unwilling to switch from current insulin therapy to investigational device for duration of the study.
• Presence of significant skin diseases/changes at sensor or infusion wear sites (for example: extensive scarring, extensive eczema, dermatitis herpetiformis, extensive burn or extensive psoriasis).
• Multifetal pregnancy.
• Inadequate access to a phone and/or computer (for downloading devices and web-based communications).
• Unable to attend required on-site study visits due to a planned move to a non-commutable distance to the study site.
• People with advanced diabetes complications such as advanced nephropathy (creatinine >1.5 mg/dl, eGFR <45 or currently on dialysis), severe autonomic neuropathy, uncontrolled gastroparesis, advanced retinopathy requiring active treatments or as per investigator judgment.
• Any bleeding disorder or hemophilia.
• Abnormal TSH 6 weeks after two consecutive titrations of thyroid medications
• Adrenal insufficiency.
• History of severe hypoglycemic event or DKA requiring hospitalization in the past 3 months or greater than 1 episode of DKA within the last year.
• Currently being treated for malignancies.
• Organ transplant recipient.
• On ultra rapid acting insulin, inhaled insulin or U200 insulin unless willing to switch to an insulin with existing data on pump compatibility.
• Daily insulin dose ≥ 1.5 units/kg/day at enrollment.
• Current use of any non-insulin glucose lowering agents except metformin, unless willing to discontinue use of said agents to participate in the study.
• Chronic oral steroid use, current oral steroid use, or high dose steroid use (oral or injectable) in the last 2 months.
• Body mass index > 40 kg/m2 at enrollment.
• Known or suspected allergy to insulin.
• Severe visual or hearing impairment preventing successful use of study system.
• Participant has any condition (physical or psychological disease) that in the opinion of the site investigator would interfere with the normal conduct and interpretation of the study results or put participant at risk during the study.
• Currently participating in another pharmaceutical or device related interventional trial at the time of enrollment or any time during the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: AID and CGM

Device: Automated Insulin Delivery (AID); The AID control algorithm, that will be used during the study employs a model-based predictive control algorithm to forecast future glucose levels. This predictive model accounts for the impact of delivered insulin, user-entered carbohydrates, and incorporates two short-term adaptations: "glucose momentum" and "retrospective correction." These features work to optimize glucose management with precision. The impact of carbohydrates is calculated based on the user-defined insulin-to-carbohydrate ratio and insulin sensitivity factor (ISF), while the insulin effect is governed by the ISF itself. The system then dynamically adjusts insulin delivery, aiming to bring glucose levels in line with the midpoint of the user's personalized glucose target range. Loop fine-tunes insulin delivery by increasing or decreasing the basal insulin rate, as needed, each time a new CGM value is received.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Time in Range 60-140 mg/dL per night	30 weeks

Collaborators and Investigators

• Sponsor: Mayo Clinic
• Collaborators: University of Colorado, Denver; Icahn School of Medicine at Mount Sinai; Stanford University
• Investigators: Principal Investigator: Yogish C. Kudva, MBBS, Mayo Clinic

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): December 1, 2028

Study Registration Dates

• First Submitted: September 2, 2026
• First Submitted That Met QC Criteria: September 2, 2026
• First Posted (Actual): September 8, 2026

Study Record Updates

• Last Update Posted (Actual): September 8, 2026
• Last Update Submitted That Met QC Criteria: September 2, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Autoimmune Diseases; Immune System Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes Mellitus, Type 1
• Other Study ID Numbers: 25-011927

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: No
• Studies a U.S. FDA-regulated device product: Yes