Gluten Challenge Study in Celiac Disease Participants (MK-0000-402)

This is a multi-site, open-label gluten challenge study to characterize peripheral blood and intestinal gluten specific CD4+ T cell subsets in participants with celiac disease (CeD). Participants will receive 8 grams (g) of gluten daily for 13 consecutive days. Blood samples will be taken at pre-dose, Day 6, and Day 14. Duodenal biopsy samples will also be collected on Day 14. Participants will also complete a symptom diary.

Inclusion criteria

• Participant must have documented diagnosis with celiac disease (CeD) by duodenal/jejunal biopsy at least 6 months prior to entrance into the study.
• Participant must be on a gluten-free diet (GFD) for at least the past 12 months.
• Female participants must not be pregnant or breastfeeding. Women of childbearing potential (WOCBP) must use an acceptable contraceptive method or abstain from heterosexual intercourse.
• Must be Human leukocyte antigen (HLA)-DQ2.5 positive, assessed at screening. If participants have already been genotyped, results from previous testing may be used in lieu of genotyping at screening.
• Has anti-tissue transglutaminase (anti-tTG) <2x upper limit of normal (ULN) as measured by serology.
• Be judged to be in good health based on medical history, physical examination (including a targeted neurological exam), versus (vs.) measurements and electrocardiogram (ECG) performed prior to treatment allocation.
• Have a body mass index (BMI) 18-35 kg/m^2, inclusive.

Exclusion criteria

• Has any chronic active gastrointestinal (GI) disease (e.g., clinically active CeD despite being on GFD for past 12 months, Crohn's disease, ulcerative colitis, lymphocytic colitis). Inactive, stable/well-treated lactose intolerance, Fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) intolerance, gastroesophageal reflux disease (GERD), and irritable bowel syndrome (IBS) are allowed.
• Has clinically active endocrine, gastrointestinal (other than CeD), cardiovascular, hematological, hepatic, immunological, renal, respiratory, genitourinary, or major neurological (including stroke and chronic seizures) abnormalities or diseases. Participants with a remote history of uncomplicated medical events or stable medical diseases with no symptoms and stable treatment for the past >3 months may be enrolled in the study at the discretion of the investigator.
• Is mentally or legally incapacitated, has significant emotional problems at the time of prestudy (screening) visit or expected during the conduct of the study or has a history of clinically significant psychiatric disorder within the last 5 years. Participants who have had situational depression may be enrolled in the study at the discretion of the investigator.
• Participant has an estimated Glomerular Filtration Rate (eGFR) ≤80 mL/min/1.73 m^2 at the screening visit based on the Cockcroft-Gault (CG) equation
• Has a history of significant multiple and/or severe allergies (e.g., food, drug, latex allergy), or has had an anaphylactic reaction or systemic allergic reaction to prescription or nonprescription drugs or food.
• Subject has a history of severe acute symptomatic reactions to sporadic gluten ingestion.
• Is positive for hepatitis B surface antigen, hepatitis C antibodies or human immunodeficiency virus (HIV).
• Had major surgery, donated or lost 1 unit of blood (approximately 500 mL) within 4 weeks prior to the prestudy (screening) visit.
• Is on Coumadin™ or other anticoagulants.
• Is unable to refrain from or anticipates the use of systemic anti-inflammatory, immunosuppressive, or immunomodulatory medications, which may include ibuprofen > 2400 mg/day, naproxen >750 mg/day, prednisone >10 mg/day, or methylprednisolone > 8 mg/day, within 48 hours prior to the start of and throughout the entire gluten challenge.
• Has participated in another investigational study within 4 weeks (or 5 half-lives, whichever is greater) prior to the prestudy (screening) visit. The window will be derived from the date of the last visit in the previous study.
• Has a corrected QT (QTc) interval ≥470 msec (for males) or ≥480 msec (for females).