The investigators are proposing a double blind, placebo-controlled trial to establish safety and efficacy of ritlecitinib to prevent gluten-induced celiac enteropathy and symptoms in celiac disease (CeD) patients in remission. The results of this study will impact the therapeutic options in the future for individuals with CeD.~Participants will take placebo capsule or ritlecitinib 200 mg capsule once per day. Both will be taken orally. All participants will take 10g gluten once per day, for a total of 21 days. Gluten will be taken orally by mixing the gluten powder into either hot chocolate or apple sauce. If participant unable to tolerate 10g of gluten daily, they will have the option to decrease to 5g daily after Day 3 of study.
Subjects include: aged 18 to 75 years, inclusive, have biopsy-confirmed disease that is clinically inactive as determined by negative celiac disease (CeD) serology and histology (determined via endoscopy at time of screening), have followed a gluten-free diet (GFD) for ≥6 months as reported by the subject, and be human leukocyte antigen (HLA)-DQ2.5 and/or HLA-DQ8 positive.~Study involves the following randomized intervention; 10g gluten + 200mg of Ritlecitinib or placebo