A Single-Arm Phase 2 Study With Optimized Standard Protocol for Severe Aplastic Anemia

During the treatment period, rATG is administered at a dose of 1.97 mg/kg/day for 9 days by slow intravenous infusion. CSA is administered orally at a dose of 3 mg/kg qod, and Levamisole was administered orally at a dose of 2.5 mg/kg qod. The CSA and Levamisole (LMS) is designed to alternately every other day.

Inclusion criteria

• Newly diagnosed SAA (according to the standard criteria)

• Bone marrow cellularity less than 30% (excluding lymphocytes)
• At least two of the following: Absolute neutrophil count less than 500/ uL; Platelet count less than 20,000/ uL; Absolute reticulocyte count less than 20,000/ uL.
• Age greater than or equal to 6 years old

Exclusion criteria

• Serum creatinine greater than 2.5 mg/dL
• Underlying carcinoma (except local cervical, basal cell, squamous cell)
• Prior immunosuppressive therapy with ATG, antilymphocyte globulin (ALG), or high dose cyclophosphamide.
• Current pregnancy or lactation or unwillingness to take oral contraceptives or use an effective method of birth control.
• Diagnosis of Fanconi anemia or other congenital bone marrow failure syndromes
• Evidence of a clonal disorder on cytogenetics. Patients with super severe neutropenia (ANC less than 200/uL) will not be excluded if results of cytogenetics are not available or pending.
• Underlying immunodeficiency state including seropositivity for HIV
• Inability to understand the investigational nature of the study or give informed consent
• Moribund status or concurrent hepatic, renal, cardiac, neurologic, pulmonary, infectious, or metabolic disease of such severity that it would preclude the patient s ability to tolerate protocol therapy, or that death within 7-10 days is likely.