Luspatercept for the Treatment of Anemia Following Allogeneic Hematopoietic Stem Cell Transplantation(Allo-HSCT)

This is a single-center, single-arm, prospective, exploratory clinical study. The study plans to enroll 46 acute leukemia patients who have undergone allo-HSCT. All enrolled subjects will receive subcutaneous luspatercept at a dose of 1 mg/kg on day +7 (±3 days) and day +28 (±3 days) post-transplantation.

Study Procedures:

The study includes a screening period, treatment follow-up visits (for drug administration), and observation follow-up visits. Intensive follow-up within 2 months post-transplant includes assessments of vital signs, physical examinations, serial hematological and biochemical tests, transfusion records, engraftment status, T-lymphocyte subset analysis (day 28), and disease-related evaluations (e.g., minimal residual disease testing, week 8). Adverse events will be continuously monitored and recorded.

Inclusion criteria

• Clinically diagnosed with acute leukemia.
• Has undergone allogeneic hematopoietic stem cell transplantation (allo-HSCT).
• Expected to survive for more than 3 months from the date of signing the informed consent form.
• Willing and able to comply with scheduled visits, treatment plans, laboratory tests, and other study procedures, and has provided written informed consent.
• Women of childbearing potential must have a negative serum pregnancy test within prior to enrollment. Female subjects who are surgically sterile or postmenopausal for at least 2 years are considered not of childbearing potential. Male and female subjects of reproductive potential must agree to use effective contraception throughout the study period.
• Hemoglobin (Hb) level < 80 g/L.

Exclusion criteria

• Inadequate organ function, defined as:

• Creatinine clearance < 60 mL/min;
• Left ventricular ejection fraction (LVEF) < 55%;
• Oxygen saturation (SpO₂) < 92% on room air;
• Total bilirubin > 2 × the upper limit of normal (ULN);
• Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 3 × ULN. 2. Poorly controlled hypertension, defined as repeated systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg despite adequate antihypertensive therapy, or a history of hypertensive crisis or hypertensive encephalopathy.

• History of other malignancies (except for acute leukemia), unless the subject has been disease-free for ≥5 years. However, subjects with the following history/concomitant conditions are eligible:

• Basal or squamous cell carcinoma of the skin;
• Carcinoma in situ of the cervix;
• Carcinoma in situ of the breast;
• Incidental histological finding of prostate cancer (T1a or T1b as defined by the TNM staging system);
• Solid tumors considered by the investigator to have no other known active disease.

• Major surgery within 8 weeks prior to enrollment. The subject must have fully recovered from any prior surgery.

• History of cerebrovascular accident (including ischemic, embolic, and hemorrhagic), transient ischemic attack, deep vein thrombosis (including proximal and distal), pulmonary or arterial embolism, arterial thrombosis, or other venous thrombosis within 6 months prior to enrollment. Note: Prior superficial thrombophlebitis is not an exclusion criterion.

• Uncontrolled epilepsy, history of cerebral ischemia/hemorrhage, cerebellar disease, or other active central nervous system disorders.

• Cardiac disease within 6 months prior to enrollment, including: myocardial infarction, uncontrolled angina, acute decompensated heart failure, New York Heart Association (NYHA) Class III-IV heart failure, or uncontrolled arrhythmia (as determined by the investigator).

• Uncontrolled active systemic fungal, bacterial, or viral infection. 9. Evidence of human immunodeficiency virus (HIV) infection, active hepatitis B, and/or active hepatitis C.

• History of pure red cell aplasia (PRCA) and/or anti-erythropoietin antibody.

• Any condition or concomitant medication that may interfere with the interpretation of study data.

• Known hypersensitivity to luspatercept or any of its excipients.