Aclarubicin Plus Cyclophosphamide, Vincristine, and Prednisone (CAOP) in Patients With Previously Treated Cutaneous T-cell Lymphoma

Inclusion Criteria:

1. Understand and voluntarily sign the informed consent form
2. Age ≥ 60 years at enrollment
3. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1
4. Histologically confirmed primary cutaneous T-cell lymphoma (CTCL) or Sézary syndrome (SS) (according to the fifth edition of the WHO Classification of Tumors of the Hematopoietic and Lymphoid System)
5. Stage II-B, III, or IV (referring to the Olsen criteria of the International Society for Cancer Research (ISCL)/USCC/EORTC, 2022)
6. Patients who have failed at least one systemic therapy; psoralen combined with ultraviolet radiation therapy (PUVA) is not considered a systemic therapy
7. All clinically significant toxicities caused by previous anticancer therapy have resolved to ≤ Grade 1 (according to NCI-CTCAE v5.0 criteria)
8. Hematological, renal, and liver function tests meet the following requirements:

   1. Absolute neutrophil count (ANC) ≥ 1,500 cells/μL
   2. Platelet count ≥ 100,000 cells/μL
   3. For patients with known bone marrow involvement, ANC ≥ 1,000 cells/μL and platelets ≥ 75,000 cells/μL
   4. Total bilirubin ≤ 1.5 times the institutional upper limit of normal (ULN) (except for patients with Gilbert syndrome)
   5. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤ 2.5 × ULN; if liver involvement is known in C TCL, ≤ 5.0 × ULN
   6. Serum creatinine ≤ 1.5 × ULN, or creatinine clearance calculated by the Cockcroft-Gault formula \> 50 mL/min

Exclusion Criteria:

1. Patients diagnosed with a malignancy within the past two years. Exclude the following situation: non-melanoma skin cancer, melanoma in situ, localized prostate cancer (current PSA \<0.1 ng/mL), treated thyroid cancer; or cervical carcinoma in situ or breast ductal/lobular carcinoma in situ diagnosed within the past two years, as long as there is no current evidence of active disease.
2. Clinical evidence of central nervous system (CNS) infiltration.
3. Large cell transformation (LCT). Patients with a history of LCT but no current invasive disease and no evidence of LCT on skin or lymph node pathology may be enrolled.
4. Psychiatric illness, disability, or social circumstances that may affect the subject's safety, ability to provide informed consent, or poor compliance.
5. Patients with significant uncontrolled comorbidities or infections, as follows:

   1. Uncontrolled infection requiring intravenous antibiotics
   2. Clinically significant heart disease (New York Heart Association class III or IV), unstable angina
   3. History of angioplasty, stent implantation, or myocardial infarction within 6 months
   4. Uncontrolled hypertension despite treatment with two antihypertensive medications (systolic blood pressure \>160 mmHg or diastolic blood pressure \>100 mmHg, measured on two consecutive occasions, one week apart)
   5. Clinically significant arrhythmias
   6. Uncontrolled diabetes mellitus
6. Known or tested positive for human immunodeficiency virus (HIV), human T-cell leukemia virus (HTLV-1), hepatitis B, or hepatitis C.
7. Active herpes simplex or herpes zoster. Patients who have started antiviral prophylaxis ≥30 days prior to the pretreatment visit, have no signs of active infection, and whose last active infection occurred more than 6 months ago may be enrolled and must continue taking prescribed medications during the study.
8. Known active autoimmune disease (e.g., Graves' disease, systemic lupus erythematosus, rheumatoid arthritis, Crohn's disease, psoriasis).
9. Allergic reaction to study medications.
10. History of allogeneic transplantation.
11. Pregnancy (confirmed by β-hCG) or lactation.