A Study of Guselkumab in Adult Participants With Celiac Disease

A Phase 1b, Randomized, Double-Blind, Placebo-Controlled Study to Assess the Safety, Pharmacokinetics, Pharmacodynamics and Clinical Response of Guselkumab in Adult Participants With Celiac Disease

The purpose of this study is to evaluate the safety and tolerability of guselkumab compared to placebo in participants with celiac disease.

Inclusion Criteria:

• Have a body mass index (BMI) 16 to 45 kilogram per meter square (kg/m^2). Underweight participants (BMI 16 to 18 kg/m^2) may only be included if in the opinion of the investigator a participant was underweight due to active celiac disease and thus, may benefit from therapy but yet not be at significantly increased risk due to severe malabsorption or other conditions
• Physician-diagnosed celiac disease with documented history of biopsy-proven celiac disease
• Self-reported to be on a gluten-free diet (GFD) for at least 11 consecutive months prior to enrollment and have the willingness to continue to adhere to the same GFD while on study
• Willing to take/ingest gluten-containing product at specific study timepoints only (if assigned to Module B)
• Willing to undergo up to 3 on-study esophagogastroduodenoscopy (EGD) with biopsies

Exclusion Criteria:

• Has a history of chronic inflammatory gastrointestinal disease (example, inflammatory bowel disease, extensive colitis, ulcerative jejunitis, eosinophilic esophagitis)
• Has chronic infectious gastrointestinal illness, or acute infectious gastrointestinal illness within the 4-week period prior to screening
• Currently has a malignancy or a history of malignancy within 5 years before screening (with the exception of a non-melanoma skin cancer that has been adequately treated with no evidence of recurrence for at least 3 months before the first study intervention administration or cervical carcinoma in situ that has been treated with no evidence of recurrence for at least 3 months before the first study intervention); known history of lymphoproliferative disease, including monoclonal gammopathy of unknown significance, lymphoma, or signs and symptoms suggestive of possible lymphoproliferative disease, such as lymphadenopathy and/or splenomegaly
• Has a history of, or ongoing, chronic or recurrent infectious disease, including but not limited to, chronic renal infection, chronic chest infection, recurrent urinary tract infection (example, recurrent pyelonephritis or chronic non-remitting cystitis), or open, draining, or infected skin wounds or ulcers
• Has had previous treatment with guselkumab