A Clinical Trial of Cidabenamine Plus Azacitidine to Prevent Post-Transplant Progression in High-Risk Peripheral T-Cell Lymphoma

Inclusion Criteria: 1. Aged 18 to 70 years, male or female. 2. Diagnosis of peripheral T-cell lymphoma (PTCL) according to the 2022 WHO criteria, including pathological subtypes such as PTCL not otherwise specified (PTCL-NOS), anaplastic large cell lymphoma (ALCL), and angioimmunoblastic T-cell lymphoma (AITL), but excluding hepatosplenic T-cell lymphoma; and meeting at least one of the following high-risk criteria: ① Stable Disease (SD) at the time of transplantation; ② Relapse after autologous hematopoietic stem cell transplantation (any disease status); ③ ≥ Partial Response 1 (PR1). 3. Underwent allogeneic peripheral blood hematopoietic stem cell transplantation for PTCL, with no restriction on donor type. 4. Presence of complete donor chimerism in the bone marrow (T-cell chimerism \>95%). 5. ECOG performance status of 0 or 1. 6. Hematological function meeting the following requirements: ① Absolute neutrophil count (ANC) ≥ 1.0 × 10⁹/L; ② Platelet count (PLT) ≥ 50 × 10⁹/L. 7. Patients must have the ability to understand and be willing to participate in the study and must provide signed informed consent. Exclusion Criteria: 1. Known hypersensitivity to hypomethylating agents or Cidabenamine. 2. Presence of grade II or higher active acute Graft-versus-Host Disease (GVHD). 3. Presence of moderate or more severe chronic GVHD. 4. Any unstable systemic disease, including but not limited to: unstable angina, cerebrovascular accident or transient ischemic attack (within 3 months prior to screening), myocardial infarction (within 3 months prior to screening), congestive heart failure (New York Heart Association \[NYHA\] Class ≥ III), status post pacemaker implantation, severe arrhythmia requiring pharmacological treatment, hepatic, renal, or metabolic disease, or pulmonary hypertension. 5. Active, uncontrolled infection, evidenced by any of the following: infection-related hemodynamic instability, worsening or new-onset infectious symptoms/signs, radiologic evidence of a new infectious focus, or persistent fever without localizing symptoms/signs where infection cannot be ruled out. 6. Known HIV infection. 7. Active Hepatitis B (HBV) or active Hepatitis C (HCV) requiring antiviral therapy. 8. History of an autoimmune disease. 9. Pregnant or lactating women. 10. Concurrent participation in another interventional clinical trial and receiving other investigational drugs.