Long-term use of the thrombopoietin-mimetic romiplostim in children with severe chronic immune thrombocytopenia (ITP). Academic Article uri icon

Overview

abstract

  • BACKGROUND: Treatment of chronic severe pediatric ITP is not well studied. In a phase 1/2 12-16-week study, 15/17 romiplostim-treated patients achieved platelet counts ≥50 × 109 /L, and romiplostim treatment was well tolerated. In a subsequent open-label extension (≤109 weeks), 20/22 patients received romiplostim; all achieved platelet counts >50 × 109 /L. Twelve patients continued in a second extension (≤127 weeks). Longitudinal data from start of romiplostim treatment through the two extensions were evaluated to investigate the safety and efficacy of long-term romiplostim treatment in chronic severe pediatric ITP. PROCEDURE: Patients received weekly subcutaneous romiplostim, adjusted by 1 µg/kg/week to maintain platelet counts (50-200 × 109 /L, maximum dose 10 µg/kg). Bone marrow examinations were not required. RESULTS: At baseline, patients were median age 10.0 years; median ITP duration 2.4 years; median platelet count 13 × 109 /L; 73% were male; and 36% had prior splenectomy. Median romiplostim treatment duration was 167 weeks (Q1, Q3: 78,227 weeks), and median average weekly dose was 5.4 µg/kg (Q1, Q3: 4.3, 8.0 µg/kg). Seven patients discontinued treatment: four withdrew consent, two were noncompliant, and one received alternative therapy. None withdrew because of adverse events (AEs). After the first 12 weeks, median platelet counts remained >50 × 109 /L. Eight (36.4%) patients received rescue medication, and 14 (63.6%) used concurrent ITP therapy. Seven patients (31.8%) reported serious AEs, and two (9.1%) reported life-threatening AEs (both thrombocytopenia); there were no serious AEs attributed to treatment and no fatalities. CONCLUSIONS: Long-term romiplostim treatment in this small cohort increased and maintained platelet counts for over 4 years in children with ITP with good tolerability and without significant toxicity. Pediatr Blood Cancer 2015;62:208-213. © 2014. The Authors. Pediatr Blood & Cancer published by Wiley Periodicals, Inc.

authors

  • Bussel, James B
  • Hsieh, Loan
  • Buchanan, George R
  • Stine, Kimo
  • Kalpatthi, Ram
  • Gnarra, David J
  • Ho, Richard H
  • Nie, Kun
  • Eisen, Melissa

publication date

  • October 24, 2014

Research

keywords

  • Blood Platelets
  • Purpura, Thrombocytopenic, Idiopathic
  • Receptors, Fc
  • Receptors, Thrombopoietin
  • Recombinant Fusion Proteins
  • Thrombopoietin

Identity

PubMed Central ID

  • PMC4309514

Scopus Document Identifier

  • 84927556174

Digital Object Identifier (DOI)

  • 10.1002/pbc.25136

PubMed ID

  • 25345874

Additional Document Info

volume

  • 62

issue

  • 2