Immune Pathway Convergence Through Dual Targeted Therapy with Upadacitinib and Ustekinumab in Refractory Ankylosing Spondylitis Associated with Crohn’s Disease: A Three-Year Follow-up Case Report

Refractory immune-mediated inflammatory diseases remain one of the greatest challenges in contemporary immunology, particularly when axial and intestinal inflammation coexist. Although sequential targeted therapies have substantially improved clinical outcomes, repeated inhibition of single inflammatory pathways may fail to achieve sustained disease control in complex immune-mediated phenotypes, suggesting that persistent inflammation reflects network-level immune dysregulation rather than isolated cytokine activation. We report a male patient diagnosed at the age of 22 years with HLA-B27-positive severe ankylosing spondylitis complicated by refractory Crohn’s disease following failure of five biologic agents targeting different inflammatory pathways. Given the complementary immunological profiles of Janus kinase (JAK1) inhibition and IL-12/23 blockade, combined therapy with upadacitinib and ustekinumab was initiated as a mechanism-oriented rescue strategy. Treatment resulted in rapid clinical improvement, normalization of inflammatory biomarkers, recovery of functional status, weight gain, marked radiological improvement of sacroiliitis, and complete endoscopic mucosal healing. Clinical remission was sustained throughout three years of follow-up without major adverse events, allowing restoration of quality of life despite previously refractory multi-organ inflammatory disease. Beyond its favorable clinical outcome, this case supports the concept that simultaneous modulation of complementary immune pathways may restore immune homeostasis when repeated sequential pathway inhibition has failed. It further illustrates how immune pathway convergence may represent a biologically rational therapeutic framework for carefully selected patients with highly refractory axial-intestinal inflammatory disease.