Efficacy and Safety of CSA and Avatrombopag for the Treatment of SAA in the Elderly

Inclusion Criteria:

1. elderly patients with V/SAA with a definite diagnosis.
2. age greater than 60 years, male or female.
3. Subjects must complete all screening assessments as outlined in the trial protocol.
4. Able to swallow or administer the drug orally.
5. Cannot tolerate or refuse ATG therapy.
6. No prior treatment with cyclosporine, tacrolimus or hormones or treatment for no morethan 2 weeks.
7. No prior application of TPO receptor agonists (including Thrombopoietin, Eltrombopag,Hetrombopag, etc.) or application of TPO receptor agonists for treatment with ≤ 5total doses and ≤ 7 days of TPO receptor agonist drugs such as Eltrombopag,Hetrombopag, etc.
8. Informed consent must be signed prior to the start of all specific study procedures,in consideration of the patient's condition, or by a member of the patient's immediatefamily if the patient's signature is not conducive to the treatment of the condition.

Exclusion Criteria: No subject shall be enrolled in this study if he/she meets any of the following criteria.

1. known diagnosis of congenital hematopoietic failure disorders (e.g. Fanconi anemia)and other causes of allogeneic cytopenias and bone marrow hypoproliferative disorders (e.g. hemolytic PNH, hypoproliferative MDS/AML, autoantibody-mediated allogeneiccytopenias, etc.);
2. Patients with uncontrolled bleeding and/or infection despite standard treatment.
3. patients with previous history of hematopoietic stem cell transplantation;
4. previous history of thrombosis.
5. Patients with concurrent malignancy or potential cancer on immunosuppressive therapy.
6. Those who are considered unsuitable for enrollment by the investigator.