Advances in the Management of Pediatric Inflammatory Bowel Disease: From Biologics to Small Molecules

<b>Background:</b> The management of pediatric inflammatory bowel disease (PIBD) has evolved significantly over the past two decades, transitioning from corticosteroids and immunomodulators to biologic and small-molecule therapies. These advances have aimed not only to control inflammation but also to promote mucosal healing, improve growth, and enhance long-term quality of life. <b>Objectives:</b> This narrative review summarizes current evidence on the efficacy, safety, and clinical applications of biologic and novel small-molecule therapies in PIBD, highlighting emerging trends in personalized and precision-based management. <b>Methods:</b> A literature search was performed across PubMed, Embase, and the Cochrane Library, focusing on studies published within the last five years. Additional data were retrieved from key guidelines and position papers issued by ECCO-ESPGHAN, SIGENP, the FDA, and the EMA. <b>Results:</b> Anti-tumor necrosis factor (TNF) agents such as infliximab and adalimumab remain first-line biologics with proven efficacy in remission induction and maintenance. Newer biologics-vedolizumab, ustekinumab, risankizumab, and mirikizumab-offer alternatives for anti-TNF-refractory cases, showing encouraging short-term results and favorable safety profiles. Although many are approved only for adults with limited pediatric evidence, emerging small molecules-including Janus kinase (JAK) inhibitors (tofacitinib, upadacitinib) and sphingosine-1-phosphate (S1P) modulators (etrasimod)-provide oral, rapidly acting, and non-immunogenic treatment options for refractory disease. Furthermore, the gut microbiome is increasingly recognized as an emerging therapeutic target in PIBD, with growing evidence that host-microbiome interactions can influence both the efficacy and safety of biologics and small-molecule therapies. <b>Conclusions:</b> While biologics and small molecules have transformed PIBD management, challenges remain, including high treatment costs, limited pediatric trial data, and variable access worldwide. Future directions include multicenter pediatric studies, integration of pharmacogenomics, and biomarker-guided precision medicine to optimize early, individualized treatment and improve long-term outcomes.