One-year Safety and Effectiveness of Ustekinumab in Patients With Crohn’s Disease: The K-STAR Study

Abstract Background This study investigated the safety and effectiveness of ustekinumab (UST) in Korean patients with Crohn’s disease (CD). Methods Adult patients with CD treated with UST were prospectively enrolled in the K-STAR (Post-MarKeting Surveillance for Crohn’s Disease patients treated with STelARa) study between April 2018 and April 2022. Both the clinical effectiveness and adverse effects of UST therapy were analyzed. Missing data were handled using nonresponder imputation (ClinicalTrials.gov Identifier: NCT03942120). Results Of the 464 patients enrolled from 44 hospitals across Korea, 457 and 428 patients (Crohn’s disease activity index ≥150) were included in the safety analysis and effectiveness analysis sets, respectively. At weeks 16 to 20 after initiating UST, clinical response, clinical remission, and corticosteroid-free remission rates were 75.0% (321 of 428), 64.0% (274 of 428), and 61.9% (265 of 428), respectively. At week 52 to 66, clinical response, clinical remission, and corticosteroid-free remission rates were 62.4% (267 of 428), 52.6% (225 of 428), and 50.0% (214 of 428), respectively. Combined effectiveness (clinical response + biochemical response) was achieved in 40.0% (171 of 428) and 41.6% (178 of 428) at week 16 to 20 and week 52 to 66, respectively. Biologic-naïve patients exhibited significantly higher rates of combined effectiveness than biologic-experienced patients (50.3% vs 30.7% at week 16-20, P .001; 47.7% vs 36.0% at week 52-66, P = .014). No additional benefits were observed with the concomitant use of immunomodulators. Ileal location was independently associated with a higher probability of clinical remission compared with colonic or ileocolonic location at week 52 to 66. Adverse and serious adverse events were observed in 28.2% (129 of 457) and 12.7% (58 of 457), respectively, with no new safety signal associated with UST treatment. Conclusions Ustekinumab was well-tolerated, effective, and safe as induction and maintenance therapy for CD in Korea.