Eltrombopag Dosing in Aplastic Anemia
The recommended dose of eltrombopag for patients with severe aplastic anemia is an initial dose of 50 mg once daily, with subsequent increases every 2 weeks up to a maximum of 150 mg daily based on platelet response. 1
Initial Dosing and Titration
- Starting dose: 50 mg once daily for 2 weeks 1
- Dose adjustments: Increase in 25 mg increments every 2 weeks if needed 1
- Maximum dose: 150 mg once daily 1, 2
- Administration: Take on an empty stomach (1 hour before or 2 hours after meals) 3
Dosing Considerations
Special Populations
- East/Southeast Asian patients: Reduce initial dose to 25 mg once daily 3
- Hepatic impairment: Reduce initial dose to 25 mg once daily 3
Response Monitoring
- Evaluate hematologic response after 12 weeks of treatment 1
- Response is defined as meeting one or more of the following criteria:
- Platelet count increase to 20 × 10⁹/L above baseline, or stable platelet counts with transfusion independence for ≥8 weeks
- Hemoglobin increase by >1.5 g/dL, or reduction in ≥4 units of RBC transfusions for 8 consecutive weeks
- ANC increase of 100% or an increase >0.5 × 10⁹/L 1
Efficacy in Aplastic Anemia
- In refractory severe aplastic anemia, eltrombopag produces an overall response rate of 40-47% 1, 4, 5
- In newly diagnosed aplastic anemia when combined with immunosuppressive therapy, response rates can reach 88-90% 6, 5
- Trilineage responses (improvement in all three blood cell lines) occur in 40-60% of responders 2, 7
Duration of Treatment
- If no response is observed after 16 weeks, eltrombopag should be discontinued 1
- For responders, treatment may be continued in the long term, with some patients maintaining response after discontinuation 1, 4
- In a study of refractory severe aplastic anemia, 8 patients achieved multilineage response, and 4 of these maintained response after discontinuing eltrombopag 1
Safety Considerations
Common Adverse Effects
- Skin pigmentation (observed in all patients taking ≥150 mg/day) 2
- Gastrointestinal upset/dyspepsia 2, 6
- Liver function test abnormalities 1, 2
Monitoring Requirements
- Regular monitoring of liver function tests 3
- Monitor for clonal cytogenetic abnormalities, which occur in 10-20% of patients 6, 5
- Bone marrow examination to assess for dysplasia, which occurs in approximately 5% of patients 7
Clinical Pearls
- Response to eltrombopag may be seen in all three cell lines (platelets, red blood cells, and neutrophils), not just platelets 4
- The medication has shown efficacy both as monotherapy in refractory disease and in combination with immunosuppressive therapy in newly diagnosed cases 6
- Higher doses (150-300 mg/day) may be required in some patients with aplastic anemia compared to other indications 2, 6
- Discontinue treatment if no response after 16 weeks 1
Eltrombopag represents an important therapeutic option for patients with aplastic anemia, particularly those who have failed immunosuppressive therapy, with the potential to reduce transfusion dependence and improve quality of life.