Clinical Study for Dimethyl Fumarate in Preserving Islet β-Cell Function in Type 1 Diabetes Mellitus

A Single-Center, Randomized, Double-Blind, Placebo-Controlled Clinical Trial Evaluating the Efficacy and Safety of Dimethyl Fumarate in Preserving Islet β-Cell Function in Patients With Type 1 Diabetes Mellitus

Purpose of the Clinical Trial:

This clinical trial aims to investigate whether dimethyl fumarate can treat adults with newly diagnosed type 1 diabetes and to evaluate the safety profile of dimethyl fumarate.

Primary Research Questions:

Does dimethyl fumarate protect pancreatic beta-cell function in adults with newly diagnosed type 1 diabetes? What medical issues may arise in individuals taking dimethyl fumarate?

Study Design:

Researchers will compare dimethyl fumarate with a placebo (an identical substance without active ingredients) to determine whether Dimethyl fumarate can effectively treat type 1 diabetes.

Participant Activities:

Take dimethyl fumarate or placebo orally twice daily for 24 weeks. Attend on-site visits every 4 weeks during the intervention period and every 12 weeks after the intervention for examinations and assessments.

Record symptoms, blood glucose control, islet function, and insulin usage throughout the trial.

Study Overview

• Status: Recruiting
• Conditions: Type 1 Diabetes
• Intervention / Treatment: Drug: Dimethyl Fumarate Enteric-coated Capsules; Drug: Matching placebo capsules

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Yong Gu; Phone Number: +86 13814084876; Email: yong.gu@njmu.edu.cn

Study Locations

• China
  • Jiangsu
    • Nanjing, Jiangsu, China, 210029
      • Recruiting
      • Deparement of Endocrinology and Metabolism, The First Affiliated Hospital with Nanjing Medical University
      • Contact: Yong Gu; Phone Number: +8613645148415; Email: yong.gu@njmu.edu.cn

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Subjects who provide written informed consent.
2. Aged 18-65 years.
3. Diagnosed with Type 1 Diabetes Mellitus (per ADA 2024 criteria).
4. Positive for ≥2 autoantibodies: Insulin autoantibody (IAA) Glutamic acid decarboxylase autoantibody (GADA) Protein tyrosine phosphatase antibody (IA-2A) Islet cell antibody (ICA) Zinc transporter 8 autoantibody (ZnT8A) Note: For IAA-positive subjects with insulin use >14 days, ≥2 additional autoantibodies must be positive.
5. Disease duration ≤100 days post-T1DM diagnosis.
6. Random C-peptide ≥ 200 pmol/L.

Exclusion Criteria:

1. Pregnancy, lactation, or women of childbearing potential not using contraception.
2. Well-controlled glycemia with oral hypoglycemic agents alone.
3. Participation in other diabetes/immune-modulating trials.
4. ALT/AST >3× upper limit of normal (ULN).
5. History of malignancy, uncontrolled autoimmune disorders, or active infections.
6. Alcohol/drug abuse, psychiatric disorders, or conditions unsuitable for trial participation.
7. Use of immunosuppressants within 12 weeks prior.
8. Participation in other drug trials within 12 weeks prior.
9. History of drug allergies, hypersensitivity, or drug addiction.
10. Any condition deemed by investigators to compromise study integrity.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dimethyl fumarate Arm; The dosing regimen for Dimethyl fumarate enteric-coated capsules initiates at 120 mg twice daily (bid). After 7 days, the dose should be escalated to the maintenance level of 240 mg bid. This investigational product is administered concurrently with standard insulin therapy for glycemic control in Type 1 Diabetes Mellitus (T1DM).	Drug: Dimethyl Fumarate Enteric-coated Capsules; The dosing regimen for Dimethyl fumarate enteric-coated capsules initiates at 120 mg twice daily (bid). After 7 days, the dose should be escalated to the maintenance level of 240 mg bid. This investigational product is administered concurrently with standard insulin therapy for glycemic control in Type 1 Diabetes Mellitus (T1DM).
Placebo Comparator: Placebo Arm; The placebo capsules initiate at a dosage of 120 mg twice daily (bid). After 7 days, the dose should be increased to the maintenance level of 240 mg bid, administered concomitantly with standard insulin-based antihyperglycemic therapy for Type 1 Diabetes Mellitus (T1DM).	Drug: Matching placebo capsules; The placebo capsules initiate at a dosage of 120 mg twice daily (bid). After 7 days, the dose should be increased to the maintenance level of 240 mg bid, administered concomitantly with standard insulin-based antihyperglycemic therapy for Type 1 Diabetes Mellitus (T1DM).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Baseline-adjusted geometric mean area under the serum C-peptide curve (C-peptide AUC) during a 2-hour mixed-meal tolerance test (MMTT) 24 weeks post-intervention.	Participants will consume a standardized liquid meal containing fixed amounts of carbohydrate, fat, and protein. Following consumption, blood glucose, C-peptide, and glucagon levels will be measured at 0-, 30-, 60-, 90-, and 120-minute time points over a 2-hour period.	Post-intervention Weeks 24

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes from baseline in the geometric mean area under the C-peptide curve (AUC-C-peptide) during the 2-hour Mixed-Meal Tolerance Test (MMTT) at Intervention Week 24 and at Weeks 24 and 52 after the end of the intervention.	Participants will consume a standardized liquid meal containing fixed amounts of carbohydrate, fat, and protein. Following consumption, blood glucose, C-peptide, and glucagon levels will be measured at 0-, 30-, 60-, 90-, and 120-minute time points over a 2-hour period.	Intervention Week 24, and Post-intervention Weeks 24 and 52
Glycemic Control Status	Hemoglobin A1c (HbA1c) levels and changes from baseline; Number of participants with poor glycemic control (HbA1c > 9%); Number of participants with good glycemic control (HbA1c < 6.5%).	Intervention Week 24, and Post-intervention Weeks 24 and 52
Mean Daily Dose of Exogenous Insulin Used During the 7 Days Preceding Each Study Visit		Intervention Week 24, and Post-intervention Weeks 24 and 52
Incidence Rates of Hypoglycemia/Severe Hypoglycemia and Ketosis/Diabetic Ketoacidosis (DKA)		Baseline, Weeks4, 8, 12, 16, 20 and 24 During Intervention, and 12, 24, 36, and 52 Weeks After Intervention
Incidence Rates of Flushing, Abdominal Pain, Diarrhea, Nausea, Vomiting, Pruritus, Rash, Proteinuria, Erythema, and Dyspepsia		Week 4, 8, 12, 16, and 24 During Intervention
Incidence Rates of Elevated Aspartate Aminotransferase (AST), Elevated Total Bilirubin (TBIL), and Lymphocytopenia		Week 4, 8, 12, 16, and 24 During Intervention
Incidence Rates of Anaphylaxis, Angioedema, and Opportunistic Infections		Week 4, 8, 12, 16, and 24 During Intervention
Baseline-adjusted geometric mean area under the curve (AUC) for serum C-peptide during a 2-hour mixed-meal tolerance test (MMTT) at 24 weeks of intervention and 52 weeks after the end of intervention.	Participants will consume a standardized liquid meal containing fixed amounts of carbohydrate, fat, and protein. Following consumption, blood glucose, C-peptide, and glucagon levels will be measured at 0-, 30-, 60-, 90-, and 120-minute time points over a 2-hour period.	Week 24 of intervention and 52 weeks post-intervention
The number of subjects who remained C-peptide positive at 52 weeks after the end of intervention (defined as a stimulated peak serum C-peptide concentration >= 200 pmol/L during a 2-hour MMTT).	Participants will consume a standardized liquid meal containing fixed amounts of carbohydrate, fat, and protein. Following consumption, blood glucose, C-peptide, and glucagon levels will be measured at 0-, 30-, 60-, 90-, and 120-minute time points over a 2-hour period.	Post-intervention Week 52
Immunological markers	Count, phenotype, and functional characteristics of white blood cell (WBC) subsets (including T cells, B cells, and natural killer [NK] cells); serum proinflammatory and regulatory cytokine profiles, along with other immune mediators; and the number of positive types, specific types, and titer levels of islet autoantibodies.	Baseline, Week 24 During Intervention, and 24,52 Weeks After Intervention

Collaborators and Investigators

• Sponsor: Nanjing Medical University
• Collaborators: The First Affiliated Hospital with Nanjing Medical University; Qilu Pharmaceutical (Hainan) Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): January 27, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2028

Study Registration Dates

• First Submitted: July 28, 2025
• First Submitted That Met QC Criteria: November 30, 2025
• First Posted (Actual): December 2, 2025

Study Record Updates

• Last Update Posted (Actual): March 5, 2026
• Last Update Submitted That Met QC Criteria: March 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Immunotherapy; Type 1 Diabetes; Pancreatic Beta-Cell Function
• 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: 2025-SR-439

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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