Improving Islet Transplantation Outcomes With Gastrin for Type I Diabetes

February 20, 2026 updated by: City of Hope Medical Center

Improving Islet Transplantation Outcomes With Gastrin

This clinical study will evaluate the safety and effectiveness of Gastrin treatment with islet transplantation to help patients with difficult to control type 1 diabetes make insulin again and improve blood sugar control.

This study involves two investigational (experimental) products not yet approved by the U.S. Food and Drug Administration (FDA) as a treatment for any disease:

  1. Human allogenic islet cells (islet cells from a deceased, unrelated human donor)
  2. Gastrin-17 (Gastrin) - a hormone secreted by the gut

Study Overview

Detailed Description

Islet cell transplantation involves transplanting the cells that make insulin from a pancreas of deceased organ donor to a patient with diabetes. Because there is a limited supply of donor islet cells available, this study is testing whether Gastrin injections can help make a fewer number of transplanted islets work better.

Gastrin is a natural gut hormone that is present in the pancreas during its development in the embryo but not after birth, and is believed to participate in the formation of the normal pancreas. Several studies have tried to use gastrin to help grow insulin making islet cells in laboratory experiments or after transplanting islets in laboratory animals. In early clinical trials, diabetic patients treated with gastrin and other growth factors required less insulin after 4 weeks of gastrin treatment and the effect lasted more than 12 weeks after stopping treatment, suggesting that gastrin may have increased the number of cells that make insulin.

This study will evaluate whether taking Gastrin injections following a single islet transplantation is safe, improves how well the islet transplant works and/or helps increase the number of insulin-making cells in the islets.

Qualified participants will receive treatment with a single islet transplant and two rounds of gastrin treatment (twice daily injections for 30 days) with transplant and again 6 months later. Study participants will also take anti-rejection medications (to prevent the body from rejecting the islet cells) and other medications to guard against infection and support their health and/or the health of the transplanted islets. Participants will need to return to City of Hope in Duarte, CA for frequent follow-up visits for one year after transplant.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Phase 2
  • Phase 1

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

  • Name: Arthur Riggs Diabetes & Metabolism Research Institute at COH
  • Phone Number: 1-866-44-ISLET(1-866-444-7538)
  • Email: Islets@coh.org

Study Locations

    • California
      • Duarte, California, United States, 91010
        • Recruiting
        • City of Hope Medical Center
        • Principal Investigator:
          • Fouad Kandeel, MD, PhD

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

Ages Eligible for Study

18 years to 68 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Age 18-68 years
  2. Type 1 diabetes mellitus (documented with fasting C-peptide level of </= 0.2 ng/ml before and </= 0.3 ng/ml after IV administration of 1 mg of glucagon) for at least 5 years.
  3. Unstable blood glucose characterized by:

    Frequent hypoglycemia (blood glucose less than or equal to 54 mg/dl more than once per week)

    -and/or- Hypoglycemia unawareness (Clarke score of 4 or more).

    -and/or- One or more severe hypoglycemic episodes in 12 months preceding enrollment

    -and/or- Erratic blood glucose levels that interfere with daily activities

    -and/or- One or more hospital visits for diabetic ketoacidosis in the 12 months preceding enrollment

  4. Ability and willingness to comply with post-transplant regimen, including immunosuppression, use of reliable contraception, frequent clinic visits, testing and maintaining detailed logs of blood glucose levels, insulin doses and medications, and completing detailed follow-up studies.
  5. Ability to give informed consent.
  6. Fully vaccinated against COVID-19

Exclusion Criteria:

  1. BMI > 33
  2. Insulin requirements > 1.0 units/kg/day
  3. Significant kidney disease (estimated GFR from serum creatinine measurement <65 ml/min, random spot urine microalbumin to creatinine ratio >300mg albumin/g creatinine)
  4. Significant hepatobiliary disease, including elevation of liver enzymes > twice the upper limit of normal for each of ALT and AST (any elevation of these enzymes will be determined), bilirubin not within normal limits, albumin < 3.5 g/dl, liver masses, portal vein thrombosis, evidence of portal hypertension, or significant, untreated gallbladder disease (i.e. gallstones)
  5. Significant cardiovascular disease, including non-correctable coronary artery disease with ejection fraction < 50% and/or recent myocardial infarction (within last 12 months); or extensive peripheral vascular disease not correctable by surgery,
  6. Evidence of active proliferative retinopathy
  7. Hypertension( >/= 140/90) despite appropriate treatment
  8. Hyperlipidemia (total cholesterol > 260 mg/dl, LDL > 160 mg/dl, and/or triglycerides > 300 mg/dl) despite appropriate treatment
  9. Anemia (Hgb < 11 g/dl) or other hematologic disorders that require medical attention
  10. WBC <3,000/ul
  11. Increased risk of bleeding (platelet count < 120,000 cells/ul; INR > 1.5), other chronic hemostasis disorders, or treatment with chronic anticoagulant therapy (i.e. heparin or warfarin)
  12. Recent unresolved acute infection (except for mild skin infection or nail fungal infection), or chronic infection, including tuberculosis, HIV, HBV, HCV, CMV or syphilis (RPR)
  13. EBV IgG negative
  14. Any history of malignancy, except completely resected squamous or basal cell skin cancer or in situ cancer of the cervix
  15. Evidence of active peptic ulcer disease
  16. History of gastric bypass
  17. Recent history of non-adherence to recommended medical therapy
  18. Psychiatric illness that is untreated, or likely to interfere significantly with study compliance despite treatment
  19. Previous organ/tissue transplant
  20. Administration of live attenuated vaccines within 60 days of enrollment.
  21. Presence of a chronic disease that must be chronically treated with contraindicated medications
  22. Use of investigational agents within four weeks of enrollment
  23. Active alcohol or substance abuse, including cigarette smoking (must be abstinent for > 3 months)
  24. Pregnant women, women intending future pregnancy, women of reproductive potential who are unable or unwilling to follow effective contraceptive measures (i.e., tubal ligation, two barrier methods, abstinence) for the duration of study treatment and for as long as they are on immunosuppressive medication, and women presently breastfeeding.
  25. Individuals without health insurance covering the cost of immunosuppression and clinical and laboratory follow-up after completion of the study
  26. Any medical condition that in the opinion of the investigator will interfere with safe participation in the trial

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Single Arm Study
islet cells transplanted into the portal vein in the liver

Gastrin-17 (or GAST-17) - a gut hormone injected under the skin twice daily for 30 days soon after islet transplant and again 6 months later.

Also, anti-rejection medications (to prevent the body from rejecting the islet cells) and other medications to guard against infection and support participant health and/or the health of the transplanted islets.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Proportion of subjects who are insulin independent, free from severe hypoglycemia and have HbA1c less than or equal to 6.5% ("complete response")
Time Frame: 1 year post transplant (6 months after second course of Gastrin)
1 year post transplant (6 months after second course of Gastrin)

Secondary Outcome Measures

Outcome Measure
Time Frame
Proportion of subjects who are free of severe hypoglycemic episodes (SHE) and have a HbA1c less than or equal to 7.0% ("partial response").
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course

Other Outcome Measures

Outcome Measure
Time Frame
Reduction/elimination of hypoglycemia
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Reduction in daily insulin use
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Reduction of daily insulin use per 100,000 IEQ transplanted
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
C-peptide/insulin secretion response to glucose/arginine stimulation and other metabolic studies.
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Incidence of treatment-related adverse events
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Incidence of a change in immunosuppression drug regimen
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
The incidence of immune sensitization defined by presence of anti-HLA antibodies absent prior to transplant
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Incidence of discontinuation of immunosuppression
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Incidence of change or early discontinuation of Gastrin treatment
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Incidence of change or early discontinuation of sitagliptin/esomeprazole supportive therapy
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Improvement in glucose time in range during continuous glucose monitoring
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
Improvement in Personal Glycemic State (PGS) score calculated from continuous glucose monitoring
Time Frame: At Month 1, Month 2.5, and Month 6 post start of each Gastrin course
At Month 1, Month 2.5, and Month 6 post start of each Gastrin course

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Fouad Kandeel, MD, PhD, City of Hope Medical Center

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.

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)

July 7, 2019

Primary Completion (Estimated)

August 1, 2028

Study Completion (Estimated)

August 1, 2028

Study Registration Dates

First Submitted

November 9, 2018

First Submitted That Met QC Criteria

November 16, 2018

First Posted (Actual)

November 20, 2018

Study Record Updates

Last Update Posted (Actual)

February 23, 2026

Last Update Submitted That Met QC Criteria

February 20, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

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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