P590 Use of upadacitinib in Refractory Paediatric Inflammatory Bowel Diseasein: A Single-Center Cohort Study

Abstract

Abstract Background Upadacitinib (UPA) is a novel selective JAK-1 inhibitor that has demonstrated efficacy in the treatment of ulcerative colitis (UC) and Crohn's disease (CD) and has received regulatory approval in adults only. Current data on the efficacy of this drug in children are limited. We report our experience in the treatment of pediatric patients with UC and CD with failure of immunosuppressive and biologic therapies. The aim of this study was to evaluate short-term effectiveness and safety UPA therapy in children with IBD. Methods Disease activity was monitored using clinical PUCAI/PCDAI scores, faecal calprotectin (FC), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), platelet. Hemoglobin (Hb), leukocyte, total cholesterol, prothrombin time, INR - international normalized ratio, fibrinogen, activated partial thromboplastin time, thrombin time were evaluated to assess side effects. At baseline biochemical and previous therapies were recorded. Results We performed a prospective analysis of clinical outcomes from January to October 2023 during UPA therapy 11 children aged 12 to 16 years (4 boys, 7 girls) 3 with UС and 8 with CD. All 11 children had received immunosuppressive and biological therapies prior to UPA prescription without success. UPA induction was administered in UC for 8 weeks and CD for 12 weeks at a dose of 45 mg once a day, then 15 mg once a day as maintenance. At the beginning 2 (18%) of 11 children had high PUCAI/PCDAI disease activity and remain 9 (82%) had mild disease activity. Elevated white blood cells was determined in 3 (27%) out of 11 children, platelet increase in 9 (82%) children, and Hb less than 110 g/L in 6 (54%) children, elevation of ESR and CRP was observed in 7 (63%) subjects. FC was elevated in 5 (62.5%) out of 8 children. Total cholesterol was normal in all patients, coagulation tests showed increased fibrinogen in 3 out of 11 children. After induction 3 (27%) of 11 children achieved remission and 8 (73%) had clinical response according to the PUCAI/PCDAI score. Elevated white blood cells was detected in 2 (18%) and decrease Hb persisted in 3 (27%) out of 11 children, elevation of ESR persisted in 5 (45%) and CRP in 6 (54%) of 11 children. FC was elevated in 6 (75%) out 8 patients. Total cholesterol and the coagulation tests remained within normal range. Side effects were not observed and UPA maintenance treatment was continued in all children. Conclusion In this real-world experience in drug-resistant pediatric patients with UC and CD we verified the efficacy and safety of UPA, but longer follow-up is needed.