Steroid-refractory acute graft-versus-host disease (SR-aGVHD) remains a major therapeutic challenge after allogeneic hematopoietic stem cell transplantation. Although ruxolitinib and basiliximab are widely used, their limitations highlight the need for safer, more effective, and scalable biologic strategies. Xenopax, a humanized anti-CD25 monoclonal antibody, has demonstrated encouraging results across real-world and clinical studies. The multicenter RELAX study reported a 28-day overall response rate of 64.5% and a 2-year overall survival of 68.0%, with reduced corticosteroid exposure and infection rates compared with historical basiliximab cohorts. Importantly, RELAX incorporated an economic assessment, showing a lower incremental cost per responder and reinforcing xenopax as a cost-efficient option for SR-aGVHD. Beyond salvage therapy, xenopax is gaining momentum in prophylactic settings, including as a potential replacement for methotrexate in haploidentical transplantation. Looking ahead, integration with autonomous decision-support systems-most notably daGOAT, the first AI platform validated to prescribe risk-adapted GVHD prophylaxis-may further strengthen CD25-targeted approaches. Together, these developments position xenopax as a versatile biologic with the potential to reshape both treatment and prevention paradigms in GVHD management.
Cao et al. (2026) studied this question.