Eltrombopag for the Treatment of Chronic Idiopathic Thrombocytopenic Purpura

TLDR

Chronic ITP results from antibody‑mediated platelet destruction and impaired production, and stimulating platelet production has been proposed as a therapeutic strategy. The study randomized 118 adults with refractory chronic ITP to oral eltrombopag (30, 50, or 75 mg daily) or placebo, with the primary endpoint of achieving ≥50 000 platelets/µL by day 43. Eltrombopag produced a dose‑dependent increase in platelet counts, achieving the primary endpoint in 28%, 70%, and 81% of patients at 30, 50, and 75 mg, versus 11% with placebo; median counts rose to 26 000, 128 000, and 183 000 /µL, and bleeding decreased, with similar adverse event rates. ClinicalTrials.gov identifier NCT00102739.

Abstract

The pathogenesis of chronic idiopathic thrombocytopenic purpura (ITP) involves antibody-mediated platelet destruction and reduced platelet production. Stimulation of platelet production may be an effective treatment for this disorder.We conducted a trial in which 118 adults with chronic ITP and platelet counts of less than 30,000 per cubic millimeter who had had relapses or whose platelet count was refractory to at least one standard treatment for ITP were randomly assigned to receive the oral thrombopoietin-receptor agonist eltrombopag (30, 50, or 75 mg daily) or placebo. The primary end point was a platelet count of 50,000 or more per cubic millimeter on day 43.In the eltrombopag groups receiving 30, 50, and 75 mg per day, the primary end point was achieved in 28%, 70%, and 81% of patients, respectively. In the placebo group, the end point was achieved in 11% of patients. The median platelet counts on day 43 for the groups receiving 30, 50, and 75 mg of eltrombopag were 26,000, 128,000, and 183,000 per cubic millimeter, respectively; for the placebo group the count was 16,000 per cubic millimeter. By day 15, more than 80% of patients receiving 50 or 75 mg of eltrombopag daily had an increased platelet count. Bleeding also decreased during treatment in these two groups. The incidence and severity of adverse events were similar in the placebo and eltrombopag groups.Eltrombopag increased platelet counts in a dose-dependent manner in patients with relapsed or refractory ITP. (ClinicalTrials.gov number, NCT00102739.)