Do I need to reduce the dose of eltrombopag/eltrombopag?

Long-term useTPO receptor agonists are common in the treatment of chronic immune thrombocytopenia (ITP). Although there is evidence that a minority of patients who receive this treatment experience remission, most patients require continued maintenance treatment. The plasma elimination half-life of Eltrombopag is 21-32 hours in healthy subjects and 26-35 hours in ITP type 1 subjects, so dosing less frequently than once a day is feasible.

When a dose reduction in the standard daily dose of eltrombopag was indicated due to a platelet count≥200×109L, the patient was switched to the same daily dose ofeltrombopag 5 days per week rather than reducing the daily dose as directed in the prescribing information. Based on patient or provider preference, platelet count reassessment was performed at 2-week intervals after reducing dosing frequency and then allowed for further reductions in dosing frequency until platelet counts stabilized in the 20-100 × 109L range or higher. This regimen provides patients with greater flexibility in meal planning, especially if patients achieve target platelet counts with once or twice weekly dosing

The prescribing information for eltrombopag recommends a starting dose of 50 mg once daily (or 25 mg for patients of East Asian race) and instructs that the daily dose be adjusted based on platelet response to achieve a target platelet count of 50-200 × 109 L. In contrast, it is recommended to start with 50-75 mg of eltrombopag daily (or 25 mg daily if East Asian) and gradually reduce the dose weekly to achieve a platelet count of ≥20 × 109 L. Although this was a modest goal chosen for its greater clinical relevance and was achieved 95% of the time according to the protocol, 84% of patients receiving intermittent dosing had platelet counts ≥50 × 109 L, the platelet count target recommended in the prescribing information.

Although for many patients, eltrombopag dosage may be the more ideal long-term treatment, providing the best balance between disease management and quality of life issues, some patients are better suited than others. Shortly after initiating eltrombopag, patients prioritized for eltrombopag had a strong response to treatment (platelet counts typically ≥200×109L). Conversely, those patients with refractory disease, mild response to daily high-dose eltrombopag therapy (platelet counts typically <50-100×109L) and difficulty remembering infrequently taken medications may be poor candidates for dosing.