Efficacy of Ustekinumab in Crohn’s Disease With and Without Concurrent Autoimmune Skin Disease

BACKGROUND: Approximately 33% of Crohn's disease (CD) patients have associated autoimmune skin disease. The pathophysiology of the latter frequently involves interleukin-12/interleukin-23 signaling pathways that may also impact gut inflammation. Ustekinumab is an anti-IL-12/23 FDA-approved biologic for psoriasis and inflammatory bowel disease. However, its relative efficacy has never been studied in CD with autoimmune skin disease (CD-ASD) vs CD without autoimmune skin disease (CD-none). METHODS: This is a retrospective, single-center, case-control study comparing markers of disease activity between CD-ASD and CD-none. Biomarkers (fecal calprotectin [FCP], C-reactive protein [CRP]) prior to drug initiation and after at least 5 months of standard IBD dose ustekinumab therapy were extracted from the medical record. In addition, 2 blinded observers performed 5-point Likert scoring before and after endoscopic, pathologic, and imaging reports. RESULTS: In all, 395 CD patients received ustekinumab therapy (79 CD-ASD, 316 CD-none). Patients were similar in age; gender; ethnicity; CD severity, phenotype, and duration; tobacco, immunomodulator, and steroid use. Ustekinumab had greater efficacy in CD-ASD when evaluated by FCP (P = .0337) and CRP (P = .078). The CD-ASD group also showed better outcomes in Likert scores of endoscopy (P = .016), histopathology (P = .074), and imaging (P = .094). In all Likert parameters, CD-ASD had more patients with complete resolution of moderate/severe disease (P < .05). Additional subanalyses for surgeries, ulcers, abscesses, fistulas, and colitis were conducted, with colitis reaching statistical significance (P = .0011). CONCLUSIONS: Concurrent autoimmune skin disease in CD is associated with greater ustekinumab effectiveness in controlling intestinal inflammation.