This study aims to evaluate the optimal dose (Recommended Phase 2 Dose, RP2D), preliminary safety, and efficacy of gecacitinib (also known as jaktinib) in combination with glucocorticoids as first-line therapy for patients with grade II-IV acute graft-versus-host disease (aGVHD) following allogeneic hematopoietic stem cell transplantation (allo-HSCT).
Voluntarily provide signed informed consent and be ≥18 years of age at the time of consent.
Recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) using bone marrow, peripheral blood stem cells, or umbilical cord blood.
Have received systemic glucocorticoid therapy for no more than 2 days prior to enrollment.
Demonstrate clear myeloid and platelet engraftment: absolute neutrophil count (ANC) > 1.0 × 10⁹/L and platelet count > 50 × 10⁹/L (permitted use of growth factors or transfusion support).
History of ≥2 allo-HSCT procedures.
Development of aGVHD following unplanned donor lymphocyte infusion (DLI) for relapse of underlying malignancy. Note: Planned DLI as part of the transplant protocol is permitted.
Concurrent treatment with another JAK inhibitor. Note: Patients who previously discontinued JAK inhibitors due to toxicity (not refractory aGVHD) are eligible.
Active bleeding.