Could a new drug help preserve insulin production in type 1 diabetes?
NCT ID NCT05574335
First seen Jun 27, 2026 · Last updated Jul 29, 2026 · Updated 2 times
Summary
This early-stage trial tested four different doses of siplizumab in 8 people aged 8–45 who were diagnosed with type 1 diabetes within the past 18 months. The goal was to find a safe dose that changes certain immune cell patterns linked to better insulin production. Participants received weekly infusions for 12 weeks and were followed for up to a year.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- siplizumab (TCD 601)
- What this could lead to
- If successful, this study could identify a siplizumab dosing regimen that helps preserve the body's ability to produce insulin in people newly diagnosed with type 1 diabetes.
- What could go wrong
- This is a very early, small trial (only 8 participants) that was terminated, so results are limited. The drug may not show meaningful benefit or could cause side effects.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 1/2
Runs two stages together: safety and dose first, then whether the treatment works.
- Participants
-
8 people
The number who actually took part.
- Started
-
May 2023
- Finished
-
Oct 2025
- Lead sponsor
-
A government research agency
The lead sponsor is the US National Institutes of Health.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
8 to 45 years
- Sex
-
Anyone
- Healthy volunteers
-
Not accepted
This study is not open to healthy volunteers. The entry requirements below say who it is open to.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: 1. Ability to provide informed consent (parental permission and informed assent of minor, if applicable). 2. Male or female between 8 to 45 years of age. 3. Diagnosis of T1DM within 18 months (550 days) of enrollment (V0). 4. Positive for at least one diabetes-related autoantibody, including: 1. Glutamate decarboxylase (GAD-65), 2. Insulin, if obtained within 10 days of the onset of exogenous insulin therapy, 3. Insulinoma antigen-2 (IA-2), or 4. Zinc transporter-8 (ZnT8). 5. Peak stimulated C-peptide level \> 0.15 nmol/L following a MMTT conducted ≥ 21 days from diagnosis and within 37 days of enrollment (V0). 6. Completion of a SARS-CoV-2 vaccination, according to current CDC recommendations and FDA approval(s) or emergency use authorization(s). If the participant requires administration of vaccine(s) to meet eligibility requirements, they must complete the vaccination series at least 2 weeks prior to enrollment (V0). Exclusion Criteria: 1. 1\. Use of investigational drugs within 24 weeks of participation with the exception of any vaccine for the prevention of SARS-CoV-2 infection and emergency use authorization medications for treating SARS-CoV-2. 2. Severe reaction or anaphylaxis to humanized monoclonal antibodies. 3. Inability to complete a mixed meal tolerance test: 1. History of significant allergy (e.g., anaphylaxis) to milk or soy proteins. 2. Inability to disable hybrid closed loop system. 4. History of recent (within 180 days of V0) or ongoing uncontrolled bacterial, viral, fungal or other opportunistic infections, including: 1. Human immunodeficiency virus (HIV), 2. Current or prior infection with hepatitis B (HBV), as indicated by positive HBsAg or positive HBcAb, 3. Current or prior hepatitis C (HCV), unless treated with anti-viral therapy with achievement of a sustained virologic response (undetectable viral load 12 weeks after cessation of therapy), 4. Positive QuantiFERON-TB Gold or QuantiFERON-TB Gold Plus tests. PPD or T-SPOT®.TB may be substituted for the QuantiFERON-TB Gold or QuantiFERON-TB Gold Plus tests, 5. Active infection with EBV as detected by PCR or serology at the screening visit (V-1), 6. Active infection with cytomegalovirus (CMV) as detected by PCR or serology at the screening visit (V-1), 5. Positive molecular testing of SARS-CoV-2 within 30 days of V-1. 6. Any of the following laboratory abnormalities confirmed by repeat tests at least 1 week apart: 1. White blood count (WBC) \< 3 x 103/μL;, 2. CD 3+ CD4+, T cell count below the lower limit of normal, 3. Platelet count \< 150,000 /μL, 4. Hemoglobin \< 10 g/dL, 5. ALT ≥ 2x upper limit of normal (ULN) or 6. AST ≥ 2x ULN 7. Serum creatinine \>1.5x ULN in adults or \>ULN in pediatrics. 8. Absolute lymphocyte count (ALC) below the LLN. 7. Prior or current treatment that is known to alter the natural history of T1DM or immunologic status, including high dose inhaled, extensive topical or systemic glucocorticoids. 8. Current or prior (within last 14 days of the V-1 MMTT) use of any medication known to influence glucose tolerance (e.g., atypical antipsychotics, diphenylhydantoin, thiazide, or other potassium-depleting diuretics, β-adrenergic blockers, niacin). 9. Current or prior (within the last 30 days of the V-1 MMTT) use of non-insulin medications to treat insulin resistance or elevated glucose levels. 10. Previous or current diagnosis of malignancy. 11. History of bone marrow transplantation, solid organ transplantation, or primary immunodeficiencies. 12. History or diagnoses of other autoimmune diseases with the exception of stable thyroid or celiac disease. 13. History of significant cardiovascular disease. 14. Vaccination with a live attenuated vaccine (e.g., varicella, measles, mumps, rubella, cold-attenuated intranasal influenza vaccine, bacillus Calmette- Guérin, and smallpox) within 30 days of V0. 15. Women of child-bearing potential who are unwilling to use a medically acceptable form of contraception from 14 days prior to V0 until study Week 52. 16. Women who are pregnant, lactating, or planning on pregnancy during the study. 17. Current, diagnosed mental illness (e.g., severe depression), current diagnosed or self-reported drug, or alcohol abuse that, in the opinion of the investigator, would interfere with the participant's ability to comply with study requirements. 18. Past or current medical problems or findings from physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.
Get updates
Get notified about this study
Sign up to get updates when this study changes or when new studies for Type 1 diabetes mellitus are added.
Genom att skicka in godkänner du våra Användarvillkor
Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
Benaroya Research Institute at Virginia Mason: Diabetes Research Program
Seattle, Washington, 98101, United States
-
Columbia University Medical Center: Naomi Berrie Diabetes Center
New York, New York, 10032, United States
-
University of Colorado School of Medicine: Barbara Davis Center for Diabetes
Aurora, Colorado, 80045, United States
-
University of Iowa Children's Hospital: Department of Pediatrics, Pediatric Endocrinology and Diabetes
Iowa City, Iowa, 52242, United States
-
University of Texas Southwestern Medical Center: Department of Internal Medicine, Division of Endocrinology
Dallas, Texas, 75390, United States
More trials for these conditions
Other studies related to the condition(s) this trial covers.
- Can a glucose sensor and family coaching tame type 1 diabetes in toddlers?
- Can a smartphone app help heal diabetic foot wounds?
- Can a handoff plan help teens with chronic illness take charge of their care?
- Cheap blood test could flag diabetic kidney damage before it strikes
- Can a common blood pressure pill protect insulin cells in kids with type 1 diabetes?
- Can a 15-Day wearable sensor keep blood sugar on target?