Brand Name: Reblozyl
Drug Class: Erythroid maturation agent (TGF-β superfamily ligand trap)
Mechanism of Action:
Luspatercept is a recombinant fusion protein that binds select TGF-β superfamily ligands, inhibiting SMAD2/3 signaling. This enhances late-stage erythroid maturation, improving red blood cell (RBC) production in patients with ineffective erythropoiesis (e.g., MDS, β-thalassemia).
FDA-Approved Indications
- Adults with very low- to intermediate-risk MDS with ring sideroblasts (RS) or SF3B1 mutation, who:
- Have failed or are ineligible for ESAs
- Are transfusion-dependent (≥2 RBC units over 8 weeks)
- β-thalassemia: For transfusion-dependent anemia (not MDS-specific)
Dosing & Administration
- Starting dose: 1 mg/kg subcutaneously every 3 weeks
- Titration: Can increase up to 1.75 mg/kg if no response after ≥2 doses
- Duration: Continue until lack of benefit, progression, or intolerance
Adverse Effects
- Hematologic: Fatigue, dizziness, headache
- Infectious: Upper respiratory tract infections
- Metabolic: Hypertension, increased uric acid
- GI: Diarrhea, nausea
- Rare but important: Thromboembolic events (especially in high-risk patients)
Monitoring Parameters
- Hemoglobin and transfusion requirements: Assess every 3 weeks
- Blood pressure: Monitor for new or worsening hypertension
- Iron studies: Patients may require iron chelation if transfusion burden continues
- Thrombotic risk: Monitor high-risk patients (e.g., prior thrombosis, advanced age)