A Study of Romiplostim for the Treatment of Refractory Transfusion-dependent NSAA

Inclusion Criteria: 1. Age ≥18 years, male or female. 2. Diagnosis consistent with refractory transfusion dependence NSAA defines refractory as patients who have failed to respond to at least 6 months of prior first-line treatment with adequate doses of cyclosporine (3-5 mg/kg) and who have been treated with an adequate dose of at least one povidone for 3 months. Definition of transfusion dependence: at least 1 component transfusion on average every 8 weeks and duration of transfusion dependence ≥ 4 months. 3. Satisfy at least one of the following conditions at the time of enrolment: haemoglobin \<90 g/L, platelets \<30×10\^9/L, neutrophils \<1.0×10\^9/L. 4. Agree to sign the consent form. 5. An Eastern Cooperative Oncology Group (ECOG) score of 0-2. Exclusion Criteria: 1. Other causes of whole blood cytopenia, such as myelodysplastic syndromes (MDS). 2. Presence of cytogenetic evidence of clonal haematological bone marrow disorders (MDS, AML). 3. PNH clones ≥50%. 4. Haematopoietic stem cell transplantation (HSCT) prior to enrolment. 5. Prior treatment with ATG. 6. Infection or haemorrhage uncontrolled by standard therapy. 7. Allergy to roprostin. 8. Active HIV, HCV or HBV infection or cirrhosis or portal hypertension. 9. Any concomitant malignancy, localised basal cell carcinoma of the skin within 5 years. 10. Liver and renal function at baseline that is more than two times normal. 11. Active infection. 12. Past history of thromboembolic events, heart attack or stroke (including antiphospholipid antibody syndrome) and current use of anticoagulants. 13. Pregnant or lactating (breastfeeding) women. 14. Participation in another clinical trial within 3 months.