Avatrombopag for the Treatment of Thrombocytopenia in Pediatric Subjects With Immune Thrombocytopenia for ≥6 Months

Inclusion Criteria: * Male or female participants ≥1 and \<18 years of age at Screening and Baseline with a diagnosis of primary ITP for ≥6 months duration and has had an insufficient response to a previous treatment, in the opinion of the Investigator. * Participant has an average of 2 platelet counts \<30×10\^9/L with no single count \>35×10\^9/L in the screening period Exclusion Criteria: * Participants must not have a known history of secondary ITP, any history of arterial or venous thrombosis, including partial or complete thrombosis, known inherited thrombocytopenia, a history of myelodysplastic syndrome (MDS) or known history of congenital heart abnormalities or arrhythmias.