A Novel Conditioning Regimen for Haplo-HSCT in Older Patients With SAA

Inclusion Criteria: * Severe aplastic anemia; * Aged 40-60 years old; * Weight 45Kg-100Kg; * Eastern Cooperative Oncology Group (ECOG) score ≤3; * No major organ injury (ECG ejection fraction \>45%; bilirubin \< 2 times the upper limit of normal value; AST and ALT \< 3 times the upper limit of normal value; serum creatinine \< 2 times the upper limit of normal value); * No severe infection; * Subjects voluntarily participated in this clinical trial and signed the informed consent. Exclusion Criteria: * With other hematologic diseases; * Expected survival of less than 1 month; * Previous autologous or allogeneic hematopoietic stem cell transplantation; * Pregnant patients; * Patients with severe mental or neurological disorders that would affect the ability to provide informed consent and/or to report or observe adverse events; * Other conditions that the investigator determines to be inappropriate for enrollment. * Current or recent (\<4 weeks prior to screening) clinically serious viral, bacterial, fungal, or parasitic infection * A history of symptomatic herpes zoster infection within 12 weeks prior to screening * Active or chronic viral infection from hepatitis B virus (HBV), hepatitis C virus (HCV), or human immunodeficiency virus (HIV) * Have evidence of active tuberculosis (TB), or have previously had evidence of active TB and did not receive appropriate and documented treatment, or have had household contact with a person with active TB and did not receive appropriate and documented prophylaxis for TB * Exposure to a live vaccine within 12 weeks prior to enrollment or expected to receive a live vaccine during the study * Clinically significant thrombotic event within 24 weeks of screening or are on anticoagulants and in the opinion of the investigator are not well controlled * Myocardial infarction (MI), unstable ischemic heart disease, stroke, or New York Heart Association Stage IV heart failure * A history or presence of cardiovascular, respiratory, hepatic, gastrointestinal, endocrine, neurological, or neuropsychiatric disorders or any other serious and/or unstable illness that, in the opinion of the investigator, could constitute an unacceptable risk when taking investigational product or interfere with the interpretation of data * Any of the following specific abnormalities on screening laboratory tests: 1. ALT or AST \>2 x ULN, or total bilirubin ≥1.5 x ULN 2. hemoglobin \<9 g/dL, or total white blood cell (WBC) count \<2,500/µL, or neutropenia (absolute neutrophil count \<1,200/µL), or lymphopenia (lymphocyte count \<750/µL) 3. eGFR \<50 mL/min/1.73 m2