Abstract Background Approximately 50% of patients with Crohn’s Disease (CD) exhibit extraintestinal manifestations (EIMs), including cutaneous conditions such as psoriasis (PSO). Recent evidence supports a bidirectional relationship between PSO and CD, underpinned by shared genetic, immunopathological, and epidemiological mechanisms, as well as overlapping therapeutic strategies. Risankizumab, an anti-IL-23 monoclonal antibody, is approved for both conditions. However, data on itsefficacy in patients affected by both PSO and CD remain limited. Methods A retrospective multicenter observational study was conducted involving patients with PSO, CD, or both, treated with risankizumab. Data were collected from the AOU Città della Salute e della Scienza di Torino and the IBD Center at Humanitas Research Hospital in Rozzano (MI), Italy. Adult patients with a confirmed diagnosis of CD and/or PSO and at least three months of follow-up were included. Efficacy in CD patients was assessed using clinical indices (HBI), endoscopic scores (SES-CD), imaging (intestinal ultrasound), and biomarkers (CRP, fecal calprotectin) at baseline (t0), 3 months (t3), and 12 months (t12) oftherapy. For PSO patients, clinical response was evaluated using PASI and DLQI at the same timepoints. The primary outcome was the rate of clinical remission (HBI 5) at 3 months in patients with PSO+CD compared to those with CD alone. Results Among 642 included patients, 84.6% (n = 543) had isolated PSO, 12.6% (n = 81) had isolated CD, and 2.8% (n = 18) had both conditions. Regarding the primary outcome, at 3 months, clinical remission was achieved by 36% of PSO+CD patients compared to 68% of those with isolated CD with a statistically significant difference (p = 0.051). At 12 months, remission rates were 80% for PSO+CD patients and 83.3% for those with isolated CD, with no statistically significant difference (p = 1.0). Other outcomes (endoscopic, ultrasound, biochemical) showed no significant differences between the groups. In PSO patients, PASI and DLQI scores significantly improved over time; over 83% achieved at least PASI75 at 12 months, and DLQI scores were below 10% of baseline showing the achievement of a great quality of life. Treatment drop-off was more frequent inthe PSO+CD group compared to PSO or CD alone. Conclusion In patients with concomitant PSO and CD, clinical remission at 3 months was lower than in those with CD alone, suggesting reduced efficacy of risankizumab for induction of remission in the presence of psoriatic comorbidity. Conversely, maintenance therapy at 12 months appeared effective, as remission rates were comparable across groups with no statistically significant differences. Conflict of interest: Prof. Ribaldone, Davide Giuseppe: No conflict of intereset Mastorino, Luca: Bezzio, Cristina: Personal Fees: I have served as a consultant or received lecture fees from AbbVie, Alfasigma, Celltrion, Eli Lilly, Ferring, Fresenius Kabi, Galapagos, Lionhealth, Johnson & Johnson, MSD, Pfizer, and Takeda Bardelli, Lucia: Santaniello, Umberto: Vernero, Marta: Ribero, Simone:
Ribaldone et al. (Thu,) studied this question.