Prospective Randomized Controlled Study: Amimaitosai Injection Combined With Corticosteroids for Gastrointestinal aGVHD

Aprospective, Randomized, Controlled Study of Amimaitosai Injection Combined With Corticosteroids for the Treatment Ofgastrointestinal Acute Graft-versus-host Disease

This study focuses on patients with gastrointestinal-dominant acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation. AmiMetosai Injection combined with corticosteroids is administered as first-line treatment. The objective is to evaluate the efficacy and safety of AmiMetosai Injection combined with corticosteroids for the treatment of gastrointestinal aGVHD.

This study focuses on patients with newly developed gastrointestinal-predominant aGVHD after allogeneic hematopoietic stem cell transplantation. The experimental group receives methylprednisolone 1 mg/kg/d combined with AmiMetosai Injection (1×10⁶ cells/kg, twice weekly for 4 weeks; extended to 8 weeks for partial responders). The control group receives methylprednisolone 2 mg/kg/d monotherapy. The primary endpoint is the Day 28 overall response rate. Secondary endpoints include GVHD-free relapse-free survival and cumulative incidence of relapse. Safety outcomes include adverse events, grade 3-4 toxicities, and abnormal laboratory parameters. Previous studies have reported that mesenchymal stromal cells are safe and effective for steroid-refractory gastrointestinal aGVHD. In this study, the combination is administered with the aim of improving treatment response and reducing corticosteroid-related toxicity.

Inclusion Criteria:

• Malignant hematologic diseases eligible for allogeneic hematopoietic stem cell transplantation, including MDS-RAEB, acute leukemia, and CML in chronic phase
• Availability of HLA-matched sibling donors, unrelated donors, or haploidentical donors
• Age 14 years and older
• Liver function: ALT and AST ≤ 2.5 times the upper limit of normal, bilirubin ≤ 2 times the upper limit of normal
• Kidney function: creatinine ≤ upper limit of normal
• No uncontrolled infections or severe psychiatric disorders
• Performance status 0-2 (ECOG)
• Signed informed consent
• Patients with acute gastrointestinal GVHD after transplantation (according to MAGIC criteria)

Exclusion Criteria:

• No suitable allogeneic donor
• Non-gastrointestinal GVHD as the main manifestation
• Either donor or recipient is pregnant
• Psychiatric illness or other conditions preventing protocol compliance