This is a prospective, single-center, single-arm, phase 2 study. This study aims to evaluate the efficacy and safety of anti-lymphocyte globulin plus herombopag in combination with the reduced dose of cyclophosphamide (hypo-CASH) for severe aplastic anemia.

Inclusion Criteria:

• Subject has a diagnosis of naïve severe or very severe aplastic anemia
• Male or female age ≥ 12 years
• Unwilling or unable to receive allogeneic hematopoietic stem cell transplantation.
• ECOG performance status ≤2
• Willing and able to comply with the requirements for this study and written informed consent.

Exclusion Criteria:

• Previously received immunosuppressive therapy > 4 weeks
• Previously treated with TPO-RA > 4 weeks
• Have an allergy or intolerance to anti-lymphocyte globulin, cyclosporine, herombopag or cyclophosphamide.
• Uncontrolled fungal, bacterial, or viral infection. Hepatitis-associated aplastic anemia is allowed; hepatitis B or C infection is permitted unless it causes severe liver failure.
• Tested positive for HIV or syphilis
• Presence of severe liver, kidney, or heart failure, or other life-threatening comorbidities.
• History of radiotherapy and chemotherapy for malignant solid tumors in recent 5 years
• Combined with other serious disorders
• Pregnant or breast-feeding patients
• Patients considered to be ineligible for the study by the investigator for reasons other than the above.