Efficacy and safety of recombinant human thrombopoietin for the treatment of chronic primary immune thrombocytopenia in children and adolescents: A multicentre, randomized, double‐blind, placebo‐controlled phase III trial

Abstract

SummaryThe efficacy and safety of recombinant human thrombopoietin (rhTPO) in children and adolescent patients with chronic primary immune thrombocytopenia (ITP) remains unclear. A multicentre, randomized, double‐blind, placebo‐controlled phase III trial was performed. Patients aged 6–17 years, diagnosed with ITP and resistant or relapsed to corticosteroid treatment were included. For the trial, part 1 was exploratory and part 2 was the main analysis, with part 1 determining whether part 2 was stratified by age. Patients in part 1 were treated with rhTPO (the 6‐ to 11‐/12‐ to 17‐year‐old groups; 1:1). Patients in part 2 were randomized (3:1) to receive either rhTPO treatment or placebo. Patients received rhTPO or placebo at a dose of 300 U/kg once daily for up to 14 days. A total of 68 patients were included [part 1 (12 patients), part 2 (56 patients)]. The total response rate (TRR) in part 1 was 50.0% (95% CI: 21.09%–78.91%). For part 2, the TRR was 58.5% (95% CI: 42.11%–73.68%) and 13.3% (95% CI: 1.66%–40.46%) in the rhTPO and placebo groups (FAS) respectively. The difference in TRR between the rhTPO group and placebo group was 45.2% (95% CI: 22.33%–68.08%) and 44.6% (95% CI: 21.27%–67.85%) on the FAS and per‐protocol set (PPS), respectively, which indicates the superiority of rhTPO treatment.