S4858 Vedolizumab as a Second Line Biologic for Cronkhite-Canada Syndrome

Introduction: Cronkhite-Canada Syndrome (CCS) is a rare, debilitating disease characterized by diffuse gastrointestinal polyposis, protein-losing enteropathy, diarrhea, and dermatologic manifestations. Nutritional support and immune modulating therapies are the mainstay of treatment. We present a case of a patient with CCS treated with vedolizumab (VDZ) to highlight an alternative treatment not discussed in the current literature. Case Description/Methods: A 67-year-old woman was diagnosed with CCS in 2020 with classic clinical symptoms and findings on endoscopy and histology. At diagnosis, her blood inflammatory markers were normal but her calprotectin was elevated (486 mcg/g). She started infliximab (IFX) and azathioprine in 10/2020 with resolution of her clinical symptoms, normalization of her calprotectin, and substantially improved but had incomplete response on repeated endoscopic and histologic evaluations. Mild residual disease was noted in the antrum. Her azathioprine was stopped due to abdominal pain, distension, nausea and vomiting and due to abnormal liver tests including elevated bilirubin. IFX was continued and the dosing was optimized to 10 mg/kg every 8 weeks with drug levels of 13.9 ug/mL. In 8/2024, she had return of her clinical symptoms, though repeat calprotectin remained normal. A repeat esophagogastroduodenoscopy and colonoscopy subsequently showed severe edema and nodularity of the antrum/duodenum and mild nodularity in the right colon. She started oral prednisone and initiated VDZ 11/2024. She gained weight and had improvement of her nails, hair, abdominal pain, and diarrhea. After 4 infusions of VDZ and 4 weeks off corticosteroids, a repeat esophagogastroduodenoscopy/colonoscopy 3/2025 showed marked improvement with only a few areas of minimal disease activity, much improved compared to the endoscopic appearance with IFX. She has continued to feel well with last follow up on 4/8/25. Discussion: When untreated, CCS can be devastating with a 5-year mortality estimated at 55% due to complications from the disease. With immunosuppressant treatment and nutritional support, a recent case series found a 5-year overall survival at 93%. While corticosteroids can be effective for disease remission; steroid-sparing strategies are preferred. Thiopurines and IFX are well described in the literature for maintaining remission. This is the first case report to date of VDZ as an alternative therapy, particularly in a patient with secondary loss of response to IFX. This highlights an important alternative treatment option.