thrombopoietin receptor agonist Phase 1 clinical study of eltrombopag, an oral, nonpeptide (original) (raw)

Eltrombopag (SB-497 115) is a first-inclass, oral, small-molecule, nonpeptide agonist of the thrombopoietin receptor (TpoR), being developed as a treatment for thrombocytopenia of various etiologies. In this phase 1 placebo-controlled clinical trial in 73 healthy male subjects, eltrombopag was administered as oncedaily oral capsules for 10 days at doses of 5, 10, 25, 30, 50, and 75 mg. The pharmacokinetics of eltrombopag were dose dependent and linear, and eltrombopag increased platelet counts in a dosedependent manner. There were no apparent differences in the incidence or severity of adverse events in subjects receiving active or placebo study medication. These observations indicate that el-trombopag is a once-daily, oral TpoR agonist with demonstrated thrombopoietic activity in human subjects, encouraging further studies in patients with thrombocytopenia. (Blood. 2007;109:4739-4741)