Open-Label Study of Dimethyl Fumarate in Adults With Type 1 Diabetes

NCT07548996 | Recruiting Phase 2 DMC

• 1 other identifier: 2026-SR-107
• Study Type: interventional
• Target: 96
• Locations: 1 country
• Sites: 1

Brief Summary

This is a non-randomized, parallel-controlled, single-center, open-label clinical trial designed to evaluate the efficacy of dimethyl fumarate in preserving pancreatic beta-cell function in adults with type 1 diabetes, as well as its safety and tolerability in this population. Eligible participants are adults aged 18 to 65 years who meet the ADA 2024 diagnostic criteria for type 1 diabetes, have at least 2 positive islet autoantibodies, and have residual beta-cell function as evidenced by a random C-peptide level of at least 200 pmol/L. A total of 96 participants are planned for enrollment, including 32 in the dimethyl fumarate treatment group and 64 in the standard-treatment control group. Participants in the treatment group will receive dimethyl fumarate enteric-coated capsules in addition to standard insulin therapy for type 1 diabetes. Dimethyl fumarate will be initiated at 120 mg twice daily and increased after 7 days to a maintenance dose of 240 mg twice daily. Participants in the control group will receive standard insulin therapy alone. The intervention period will be 24 weeks, followed by 52 weeks of follow-up. The primary efficacy endpoint is the baseline-adjusted geometric mean area under the serum C-peptide curve during a 2-hour mixed-meal tolerance test at Week 24. Secondary endpoints include measures of beta-cell function at multiple time points, changes in glycated hemoglobin, proportions of participants with good or poor glycemic control, insulin dose requirements, and immunologic markers including lymphocyte subsets, cytokine profiles, and islet autoantibody characteristics. Safety assessments will include the incidence of flushing, gastrointestinal adverse events, allergic reactions, opportunistic infections, liver function abnormalities, lymphopenia, renal abnormalities, hypoglycemia, severe hypoglycemia, ketosis, and ketoacidosis. The total study duration is 36 months, from January 2026 to December 2028.

Conditions

Type 1 Diabetes Mellitus

Keywords

Dimethyl Fumarate; Type 1 Diabetes; Beta-Cell Function

Outcome Measures

Primary Outcomes (1)

• Baseline-Adjusted Geometric Mean Area Under the Serum C-Peptide Curve During a 2-Hour Mixed-Meal Tolerance Test

  The primary efficacy endpoint is the baseline-adjusted geometric mean area under the serum C-peptide curve during a 2-hour mixed-meal tolerance test (MMTT).

  24 weeks after end of intervention (48 weeks after enrollment)

Secondary Outcomes (24)

• Baseline-Adjusted Geometric Mean Area Under the Serum C-Peptide Curve During a 2-Hour Mixed-Meal Tolerance Test

  End of intervention (24 weeks after enrollment) and 52 weeks after end of intervention (76 weeks after enrollment)

• Change From Baseline in Geometric Mean Area Under the Serum C-Peptide Curve During a 2-Hour Mixed-Meal Tolerance Test

  End of intervention (24 weeks after enrollment), 24 weeks after end of intervention (48 weeks after enrollment), and 52 weeks after end of intervention (76 weeks after enrollment)

• Number of Participants Maintaining Positive C-Peptide Response After a 2-Hour Mixed-Meal Tolerance Test

  52 weeks after end of intervention (76 weeks after enrollment)

• Glycated Hemoglobin (HbA1c)

  End of intervention (24 weeks after enrollment), 24 weeks after end of intervention (48 weeks after enrollment), and 52 weeks after end of intervention (76 weeks after enrollment)

• Number of Participants With Poor Glycemic Control

  End of intervention (24 weeks after enrollment), 24 weeks after end of intervention (48 weeks after enrollment), and 52 weeks after end of intervention (76 weeks after enrollment)

Study Arms (2)

Dimethyl Fumarate Plus Standard Insulin Therapy

EXPERIMENTAL

Participants in this arm will receive dimethyl fumarate enteric-coated capsules in addition to standard insulin therapy for type 1 diabetes. Dimethyl fumarate will be initiated at 120 mg twice daily and increased after 7 days to 240 mg twice daily. The intervention period will last 24 weeks, followed by 52 weeks of follow-up.

Drug: Dimethyl Fumarate Enteric-coated Capsules; Drug: Insulin

Standard Insulin Therapy

ACTIVE COMPARATOR

Participants in this arm will receive standard insulin therapy for type 1 diabetes without dimethyl fumarate. Participants will be followed according to the study schedule for 24 weeks of treatment observation and 52 weeks of follow-up.

Drug: Insulin

Interventions

Dimethyl Fumarate Enteric-coated Capsules DRUG

Dimethyl fumarate enteric-coated capsules, initiated at 120 mg twice daily and increased after 7 days to 240 mg twice daily.

Also known as: DMF

Dimethyl Fumarate Plus Standard Insulin Therapy

Insulin DRUG

Standard insulin therapy for type 1 diabetes according to routine clinical practice.

Dimethyl Fumarate Plus Standard Insulin Therapy; Standard Insulin Therapy

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Willing and able to participate in the study and provide signed informed consent
• Aged 18 to 65 years
• Diagnosed with type 1 diabetes mellitus according to ADA 2024 criteria
• Positive for at least 2 islet autoantibodies among insulin autoantibody (IAA), glutamic acid decarboxylase autoantibody (GADA), insulinoma-associated protein 2 autoantibody (IA-2A), islet cell antibody (ICA), and zinc transporter 8 autoantibody (ZnT8A)
• Random C-peptide level greater than or equal to 200 pmol/L
• Note:
• \- For participants who have used insulin for more than 14 days, a positive IAA result must be accompanied by at least 2 additional positive autoantibodies other than IAA

You may not qualify if:

• Pregnant or breastfeeding women, positive urine pregnancy test at screening, or inability to rule out pregnancy in the opinion of the investigator
• Good glycemic control with oral antidiabetic drugs alone
• Participation in other studies involving diabetes treatment or immunomodulation
• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) greater than 3 times the upper limit of normal
• Renal insufficiency or evidence of kidney damage, including estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m², urinary albumin-to-creatinine ratio (UACR) greater than or equal to 3.4 mg/mmol (repeat confirmation if necessary), or other kidney disease considered unsuitable for enrollment by the investigator
• History of malignancy, uncontrolled immune system disease, or uncontrolled infection
• Alcohol abuse, drug abuse, psychiatric disorder, or other conditions considered unsuitable for participation in a drug trial
• Use of other immunosuppressive agents within 12 weeks before enrollment
• Participation in any other drug trial within 12 weeks before enrollment
• History of multiple drug allergies, allergic diseases, hypersensitivity constitution, or drug dependence
• Any disease or condition that, in the opinion of the investigator, may interfere with study participation or evaluation

Sponsors & Collaborators

• Nanjing Medical University: lead

Study Sites (1)

Jiangsu Provincial Hospital

Nanjing, Jiangsu, 210029, China

RECRUITING

MeSH Terms

Conditions

Diabetes Mellitus, Type 1

Interventions

Insulin

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases

Intervention Hierarchy (Ancestors)

Proinsulin; Insulins; Pancreatic Hormones; Peptide Hormones; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Peptides; Amino Acids, Peptides, and Proteins

Study Officials

• Yong Gu

  Department of Endocrinology, Jiangsu Provincial Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Yong Gu

CONTACT

+86 13814084876; yong.gu@njmu.edu.cn

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor, Chief Physician, Deputy Director, Department of Endocrinology

Study Record Dates

• First Submitted: April 14, 2026
• First Posted: April 23, 2026
• Study Start: April 27, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: April 23, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)