Dynamic dosing of romiplostim in patients with immune thrombocytopenia purpura: Two case reports

J Oncol Pharm Pract. 2019 Apr;25(3):719-723. doi: 10.1177/1078155217752536. Epub 2018 Jan 22.

Abstract

Romiplostim is a thrombopoietin receptor agonist approved for the treatment of immune thrombocytopenia purpura. When following FDA-approved romiplostim prescribing recommendations to withhold treatment for platelet counts above 400k/µL, some patients exhibit a precipitous decline in their platelet count potentially causing patient harm. We present two cases where stable platelet counts were achieved only through persistent weekly dosing of romiplostim despite platelet counts above 400k/µL on the day of administration. Therefore, continuous weekly dosing of romiplostim despite platelet count being above 400k/µL combined with twice weekly vigilant monitoring is an alternative method of romiplostim dosing that mitigates severe fluctuations in platelets. We also discuss important details, postulated mechanisms, and evidence-based mitigation strategies.

Keywords: Immune thrombocytopenic purpura; benign hematology; romiplostim; thrombopoietin receptor agonist.

Publication types

  • Case Reports

MeSH terms

  • Aged
  • Female
  • Humans
  • Male
  • Middle Aged
  • Platelet Count
  • Purpura, Thrombocytopenic, Idiopathic / drug therapy*
  • Receptors, Fc / administration & dosage*
  • Receptors, Thrombopoietin / agonists*
  • Recombinant Fusion Proteins / administration & dosage*
  • Thrombopoietin / administration & dosage*

Substances

  • Receptors, Fc
  • Receptors, Thrombopoietin
  • Recombinant Fusion Proteins
  • Thrombopoietin
  • romiplostim