This is a two-part, double-blind, randomized, placebo-controlled, and open-label Phase III study to investigate the efficacy, safety of Hetrombopag in pediatric patients with previously treated chronic ITP. In Part A, patients will receive Hetrombopag for 8 weeks. After completing Part A, patients will begin Part B, in which they will be randomized to receive Hetrombopag or placebo in a 12 week double-blind, placebo-controlled treatment period, following an open-label 12 week treatment period.
The purpose of this study is to investigate the efficacy, safety of Hetrombopag in children with previously treated chronic immune thrombocytopenia who are between 6 and 17 years of age. This is a 2 part study. In part A, patients will receive Hetrombopag for 8 weeks. In part B, all patients will receive Hetrombopag for 24 weeks.