Number of Participants With the Indicated Vital Signs Falling Outside of the Reference Range During Part 1, Part 2, and Part 2/3

Part 1 Eltrombopag Dose-Finding Period

Participants (par) aged between 1 and 17 years (Cohort 1 age group: 12 to 17 years, Cohort 2: 6 to 11 years and Cohort 3:1 to 5 years) received eltrombopag for 24 weeks. The starting dose for Cohort 1 was 25 mg, and par of East Asian ancestry received 12.5mg QD. For cohort 2 starting dose was based on the body weight. Par with a bodyweight of \<27 kg received 12.5 mg QD, par with a body weight of \>=27 kg received 25 mg QD; par of east Asian ancestry with a body weight \<27 kg received 12.5 mg QD, and with a body weight of \>=27 kg received 25 mg QD. For Cohort 3, the starting dose was 0.7 mg/kg QD and 0.5 mg/kg/day for par of East Asian ancestry and the dose calculations were based on the body weight. The maximum dose allowed for all Cohorts was 75mg daily. For all par, individual dose titration was allowed based upon platelet response.

Part 2 Randomized Period - Placebo

Par aged between 1 and 17 years (Cohort 1 age group: 12 to 17 years, Cohort 2: 6 to 11 years and Cohort 3:1 to 5 years) received eltrombopag matching placebo for 7 weeks.

Part 2 Randomized Period - Eltrombopag

Par aged between 1 and 17 years (Cohort 1 age group: 12 to 17 years, Cohort 2: 6 to 11 years and Cohort 3:1 to 5 years) received eltrombopag for 7 weeks. The starting dose for Cohort 1 was 37.5 mg QD. For Cohort 2, starting dose was based on the body weight. Par with a body weight of \<27 kg received 25 mg QD, and par with a body weight of \>=27 kg received 50 mg QD. Par of East Asian ancestry with a body weight of \<27 kg received 12.5 mg QD, and with a body weight of \>=27 kg received 25 mg QD. For Cohort 3, the starting dose was 1.5 mg/kg QD and 0.8 mg/kg/day for par of East Asian ancestry. The maximum dose allowed was 2mg/kg and could not exceed 75 mg daily. For all par, individual dose titration was allowed based upon platelet response.

Part 2/ 3 (Eltrombopag Open-Label Period)

Par aged between 1 and 17 years (Cohort 1 age group: 12 to 17 years, Cohort 2: 6 to 11 years and Cohort 3: 1 to 5 years), completing Part 2 of the study received an Open -Label treatment of eltrombopag administered as a tablet or dry powder for oral suspension in Part 2/3. Par who received eltrombopag during the Randomized Period continued on the same dose, unless adjustments were warranted according to the dosing guidelines, for 17 additional weeks (for a total of 24 weeks of treatment). Par who received placebo during the Randomized Period followed the starting doses for each age Cohort specified for Part 2, and received a total of 24 weeks of eltrombopag treatment.

Analysis denominator · Participants