Early predictors of pruritus response in children with PFIC treated with odevixibat

Background: In our previous study we reported the efficacy of odevixibat treatment (OT) in a real-world cohort of children with progressive familial intrahepatic cholestasis (PFIC). Here we aim to identify the best cut-off of serum bile acid (sBA) early reduction predicting the response of pruritus at 6 months of treatment. Methods: We reviewed data on children with PFIC treated with odevixibat. ROC analysis was performed to calculate the best cut-off of sBA reduction at 1 and 3 months associated with reduction in pruritus scale ≥1 point at 6 months. Results: 24 patients [median age 6.6 years (3.7–12.1), M/F = 11/13] were enrolled; 16 (67%) had classic PFIC types (PFIC-1 = 2; PFIC-2 = 11; PFIC-3 = 3), 8 (33%) had rarer forms (PFIC-4 = 5, PFIC-5 = 1; PFIC-6 = 1; PFIC-9 = 1). At 6 months, 73% were pruritus responders. Reductions of sBA levels ≥48% from baseline at 1 month and ≥52% at 3 months were associated with improvements of pruritus at 6 (1st month: ROC-AUC 0.771; SE=0.75, SP=0.83; 3rd month: ROC-AUC 0.885; SE=0.81, SP=1.00). Conclusion: reduction of sBA levels of around 50% from baseline value at 1 and 3 months is associated with a pruritus response to OT at 6 months. This information could be useful to the management of children with PFIC.