Thrombopoietin Receptor Agonist Use in Children: Data From the Pediatric ITP Consortium of North America ICON2 Study

• Type of Material: Article
• Authors: Cindy Neunert, Columbia University; Jenny Despotovic, Baylor College of Medicine; Kristina Haley, Oregon Health and Sciences University; Michele P. Lambert, University of Pennsylvania; Kerri Nottage, St. Jude Children’s Research Hospital; Kristin Shimano, University of California San Francisco; Carolyn Bennett, Emory University; Robert Klaassen, University of Ottawa; Kimo Stine, University of Arkansas Medical Sciences; Alexis Thompson, Ann and Robert H. Lurie Children’s Hospital of Chicago; Yves Pastore, University of Montreal; Travis Brown, Dana-Farber/Boston Children’s Cancer and Blood Disorders Center; Peter W. Forbes, Boston Childrens Hospital; Rachael F. Grace, Dana-Farber/Boston Children’s Cancer and Blood Disorders Center
• Language: English
• Date: 2016-08-01
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2016 Wiley Periodicals, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1002/pbc.26003
• Title of Journal or Parent Work: Pediatric Blood and Cancer
• ISSN: 1545-5009
• Volume: 63
• Issue: 8
• Start Page: 1407
• End Page: 1413
• Grant/Funding Information: This work was funded by the Terrana fund for ITP research (Boston Children’s Hospital); and NIH K12 HL087164 grant funding (RG).
• Keywords: DOUBLE-BLIND; pediatrics; CHRONIC IMMUNE THROMBOCYTOPENIA; ELTROMBOPAG; Science & Technology; Hematology; EFFICACY; PURPURA ITP; ICON; Pediatrics; treatment; thrombopoietin receptor agonists; Oncology; ROMIPLOSTIM; LONG-TERM TREATMENT; Life Sciences & Biomedicine; PLACEBO-CONTROLLED TRIAL; OPEN-LABEL; immune thrombocytopenia; JAPANESE PATIENTS
• Research Categories: Health Sciences, Pathology; Health Sciences, Oncology

Abstract

Background: Data on second-line treatment options for pediatric patients with immune thrombocytopenia (ITP) are limited. Thrombopoietin receptor agonists (TPO-RA) provide a nonimmunosuppressive option for children who require an increased platelet count. Procedure: We performed a multicenter retrospective study of pediatric ITP patients followed at ITP Consortium of North America (ICON) sites to characterize TPO-RA use. Results: Seventy-nine children had a total of 87 treatments (28 eltrombopag, 43 romiplostim, and eight trialed on both). The majority had primary ITP (82%) and most (60.8%) had chronic ITP. However, 22% had persistent ITP and 18% had newly diagnosed ITP. During the first 3 months of treatment, 89% achieved a platelet count ≥ 50 × 10 9 /l (86% romiplostim, 81% eltrombopag, P = 0.26) at least once in the absence of rescue therapy. The average time to a response was 6.4 weeks for romiplostim and 7.0 weeks for eltrombopag (P = 0.83). Only 40% of patients demonstrated a stable response with consistent dosing over time. An intermittent response with constant dose titration was seen in 15%, and an initial response that waned to no response was seen in 13%. Significant adverse events were minimal with the exception of two patients with thrombotic events and one who developed a neutralizing antibody. Conclusions: Our results demonstrate that TPO-RA agents are being used in children with ITP of varying duration and severity. The response was similar to clinical trials, but the sustainability of response varied. Future studies need to focus on the ideal timing and rationale for these medications in pediatric patients.