A Clinical Study Evaluating the Safety and Efficacy of GT729 Universal Cell Injection in the Treatment of Refractory or Relapsed Chronic Graft-versus-host Disease (cGVHD)

Inclusion Criteria: * Participants or their legal representatives voluntarily sign a written informed consent form, are willing and able to comply with the procedures of this study. * Aged 18 to 65 years old (inclusive) when signing the informed consent, regardless of gender. * Participants must meet the following criteria: 1. The subjects are allogeneic hematopoietic stem cell transplantation (alloHSCT) recipients with active chronic graft-versus-host disease (active cGVHD) requiring systemic immunosuppressive therapy. 2. The subjects are patients with refractory or relapsed active cGVHD after receiving at least two lines of systemic treatment. * The laboratory test results during the screening period must meet the following criteria (except for indicators related to the study disease): 1. Neutrophil count ≥ 1.0×10⁹/L; 2. Hemoglobin ≥ 80g/L; Platelet count ≥ 30×10⁹/L; 3. Alanine transaminase ≤ 3×upper limit of normal (ULN); Aspartate transaminase ≤ 3×ULN; Total bilirubin (TBIL) \< 2×ULN; 4. Creatinine clearance rate ≥ 30 mL/min. * Women of childbearing age must: At the time of screening, as confirmed by the investigator, the result of the serum β-human chorionic gonadotropin (β-hCG) pregnancy test is negative. Exclusion Criteria: * Evidence of recurrence of underlying malignant tumors or post-transplant lymphoproliferative disorder (PTLD) at the time of screening * Having a history of severe hypersensitivity or allergies * Suffering from the following heart diseases: 1. New York Heart Association (NYHA) Class III or IV congestive heart failure; 2. A myocardial infarction occurred or coronary artery bypass surgery was performed within 6 months before the screening period. * Participants with clinically significant bleeding symptoms or a clear bleeding tendency within the 6 months prior to screening; * Participants with severe underlying medical conditions at the time of screening; * Participants who have undergone major surgery within 8 weeks prior to screening or are scheduled to undergo surgery during the study period; * History of organ transplantation; * According to the investigator's judgment, there are circumstances that would prevent the participant from completing the entire trial, confuse the trial results, or make participation in the trial not in the best interest of the participant.