Ustekinuma b for Crohn's Disease: Two-Year Results of the Initiative on Crohn and Colitis (ICC) Registry, a Nationwide Prospective Observational Cohort Study.

Aims: Ustekinumab is a monoclonal antibody that selectively targets p40, a shared subunit of the cytokines interleukin [IL]-12 and IL-23. It is registered for the treatment of inflammatory bowel diseases. We assessed the 2-year effectiveness and safety of ustekinumab in a real world, prospective cohort of patients with Crohn's disease [CD].

Methods: Patients who started ustekinumab were prospectively enrolled in the nationwide Initiative on Crohn and Colitis [ICC] Registry. At weeks 0, 12, 24, 52 and 104, clinical remission Harvey Bradshaw Index≤ 4 points], biochemical remission (faecal calprotectin ≤ 200 μg/g and/or C-reactive protein ≤5 mg/L], perianal fistula remission, extra-intestinal manifestations, ustekinumab dosage and safety outcomes were determined. The primary outcome was corticosteroid-free clinical remission at week 104.

Results: In total, 252 CD patients with at least 2 years of follow-up were included. Of all included patients, the proportion of patients in corticosteroid-free clinical remission was 32.3% [81/251], 41.4% [104/251], 39% [97/249] and 34.0% [84/247] at weeks 12, 24, 52 and 104, respectively. In patients with combined clinical and biochemical disease activity at baseline [n = 122], the corticosteroid-free clinical remission rates were 23.8% [29/122], 35.2% [43/122], 40.0% [48/120] and 32.8% [39/119] at weeks 12, 24, 52 and 104, respectively. The probability of remaining on ustekinumab treatment after 52 and 104 weeks in all patients was 64.3% and 54.8%, respectively. The main reason for discontinuing treatment after 52 weeks was loss of response [66.7%]. No new safety issues were observed.

Conclusion: After 104 weeks of ustekinumab treatment, one-third of CD patients were in corticosteroid-free clinical remission.