Mini- dose methotrexate combined with methylprednisolone as a first-line treatment for acute graft-versus-host disease: A phase 2 trial

Background and Objectives: Acute graft-versus-host disease ( aGvHD) remains a major complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Methylprednisolone (MP; 1-2 mg/kg/day) remains the standard first-line therapy for aGvHD, although no response is detected in nearly one-half of the patients with aGvHD. This study aimed to investigate the feasibility of mini-dose methotrexate (MTX) combined with standarddose MP as a front-line therapy for aGvHD. Materials and Methods: A prospective Phase 2 clinical trial was performed to evaluate the safety and efficacy of 5 mg/m2 MTX combined with 1 mg/kg/day MP as the initial therapy in 31 patients with aGvHD. Moreover, the effects of MTX combined with MP were explored in a humanized xenogeneic murine model of aGvHD. Results: The overall response and complete response rate at 7 days after the initial treatment were 100% and 83%, respectively. The overall response rate on day 28 was 87%. The complete response rates for aGvHD grades I, II, and III were 100% (6/6), 82% (18/22), and 66% (2/3), respectively. Grade 3 toxicities occurred in only three patients presenting with cytopenia. Importantly, MTX and MP demonstrated synergistic effects on ameliorating aGvHD in humanized xenogeneic murine model. Conclusion: The current study suggests that mini-dose MTX combined with standard-dose MP could potentially become a novel firstline therapy for patients with aGvHD.