Protocol Number: 09-DK-0055

Title:

Assessment of the Effects of a DPP-4 Inhibitor (Sitagliptin) Januvia on Immune Function in Healthy Individuals

Number:

09-DK-0055

Summary:

Patients with diabetes have high blood sugar levels (hyperglycemia) because pancreatic beta-cells no longer produce sufficient insulin. Insufficient beta-cell function can be caused by an autoimmune killing of the beta-cells in type 1 diabetes (T1D), or by poorly understood mechanisms in type 2 diabetes (T2D). Glucagon-like peptide-1 (GLP-1) improves function of the insulin-producing beta cells, but GLP-1 has a very short circulating half-life because it is cleaved by the enzyme dipeptidyl peptidase IV (DPP-4). One current treatment being used to improve glycemia control in patients with T2D is sitagliptin, an inhibitor of DPP-4. By inhibiting DPP-4, sitagliptin increases GLP-1 levels, resulting in improved beta cell function. Sitagliptin is now being tested in individuals with new-onset T1D to determine whether it may help to preserve beta cell function. Because T1D is a disease in which the immune system destroys the insulin-producing beta cells in the pancreas, we wish to determine if and how sitagliptin alters immune function. Sitagliptin has been shown by Merck to be safe and effective with no overt immuno-toxicities. However, several lines of evidence suggest that DPP-4 inhibitors such as sitagliptin could be immunomodulatory.

This randomized clinical trial will study immune function in healthy volunteers given short-term (4 week) treatment with either sitagliptin or placebo. During the study, we will take blood samples at various time intervals before, during and after treatment. We will compare the immune response with and without sitagliptin treatment using blood samples from healthy individuals. We will measure changes in the magnitude and type of immune responses. The study period is nine weeks. The study's primary outcome will be changes in blood plasma levels of a protein marker associated with decreased inflammation: Transforming Growth Factor Beta 1 (TGF beta 1). In addition, we plan to use these blood samples to measure sitagliptin's effect on expression levels of several cytokines (immune proteins). We will also measure the level of proliferation in stimulated PBMCs (blood immune cells) and gene expression in whole blood after sitagliptin treatment.

Sponsoring Institute:

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Recruitment Detail

Type: Participants currently recruited/enrolled

Gender: Male & Female

Referral Letter Required: No

Population Exclusion(s): Children

Eligibility Criteria:

INCLUSION CRITERIA:

Age greater than 18

Fasting blood glucose less than 100 mg/dl, and a normal Hgb A1c (less than 6.4%),

Available for follow up through 9 weeks.

In good general health without clinically significant medical history as deemed by study investigators.

Hemoglobin greater than 12.5 mg

EXCLUSION CRITERIA:

History of diabetes or other autoimmune diseases including (but not limited to) rheumatoid arthritis, lupus, multiple sclerosis.

Active hepatitis B, C and/ or HIV infection.

Recent diagnosis or active treatment for malignancy.

Recent (within 3 weeks) severe allergy symptoms such as allergy-induced asthma, skin eruptions or urticaria.

Recent (within 3 weeks) viral or bacterial infections.

History of other immune abnormalities or the presence of disease processes that, in the opinion of the investigator, may alter immune function.

Pregnant and nursing females.

Women who have child-bearing potential but not using adequate birth control.

History of hypersensitivity reaction to sitagliptin.

Special Instructions:

Currently Not Provided

Keywords:

Immune Function

DDP-4

Sitagliptin

GLP-1

TGF Beta

Recruitment Keyword(s):

None

Condition(s):

Diabetes Mellitus Type 1

Diabetes Mellitus Type 2

Investigational Drug(s):

None

Investigational Device(s):

None

Intervention(s):

Drug: Sitagliptin (Januvia)

:

:

Supporting Site:

National Institute of Diabetes and Digestive and Kidney Diseases

Contact(s):

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793

Electronic Mail:prpl@mail.cc.nih.gov

Citation(s):

Drucker DJ. Glucagon-like peptide-1 and the islet beta-cell: augmentation of cell proliferation and inhibition of apoptosis. Endocrinology. 2003 Dec;144(12):5145-8.

Thompson MA, Ohnuma K, Abe M, Morimoto C, Dang NH. CD26/dipeptidyl peptidase IV as a novel therapeutic target for cancer and immune disorders. Mini Rev Med Chem. 2007 Mar;7(3):253-73.

Amori RE, Lau J, Pittas AG. Efficacy and safety of incretin therapy in type 2 diabetes: systematic review and meta-analysis. JAMA. 2007 Jul 11;298(2):194-206.

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