TL1A as a therapeutic renaissance in inflammatory bowel disease: a systematic review from molecular mechanisms to clinical translation

Background and Aims: Despite major therapeutic advances, many patients with inflammatory bowel disease (IBD) continue to experience inadequate treatment response, progressive disease, and irreversible complications requiring surgery. Current management is constrained by a biological efficacy ceiling and lack of agents directly targeting key drivers of fibrosis and barrier dysfunction. This systematic review synthesizes current knowledge on tumor necrosis factor-like cytokine 1A (TL1A) and death-domain receptor 3 (DR3) signaling pathways, critically evaluates the therapeutic potential of TL1A-targeted interventions, and explores future directions for precision medicine applications in IBD care. Methods: A comprehensive systematic search of PubMed, EMBASE, Cochrane library, Web of Science, and ClinicalTrials.gov was conducted according to PRISMA guidelines. Three independent reviewers screened preclinical and clinical studies using Rayyan software. Study selection, data extraction, and quality assessment were performed in duplicate. Eligible studies underwent narrative thematic synthesis. Results: Of 250 studies identified, 63 met inclusion criteria. Preclinical data consistently demonstrate TL1A-DR3 signaling drives inflammation, fibrosis, and barrier dysfunction. Phase 2 clinical trials showed anti-TL1A monoclonal antibodies (Tulisokibart, Afimkibart, Duvakitug) achieved clinical remission/response rates between 26% and 66% in patients with moderate-to-severe IBD at 12-14 weeks, with favorable safety profiles. Emerging themes include extended dosing intervals, therapeutic benefit in treatment-refractory populations, potential anti-fibrotic effects, and opportunities for biomarker-guided patient stratification. Conclusion: TL1A inhibitors represent a promising novel therapeutic class with dual anti-inflammatory and anti-fibrotic properties, addressing critical unmet clinical needs in IBD. These agents hold the potential to become cornerstone therapies in the evolving landscape of precision medicine for IBD care.