Drugs. 2009;69(3):307-17. doi: 10.2165/00003495-200969030-00006.


*Romiplostim is an Fc-peptide fusion protein (or 'peptibody') that stimulates megakaryopoiesis and thrombopoiesis by binding to, and activating, the thrombopoietin receptor. *Because it has no sequence homology to thrombopoietin, romiplostim theoretically avoids the risk of eliciting cross-reacting, neutralizing antibodies to thrombopoietin. *In well designed, 24-week, phase III trials, subcutaneous romiplostim was significantly more effective than placebo in achieving the primary endpoint of a protocol-defined durable platelet response in nonsplenectomized (61% vs 5%) or splenectomized (38% vs 0%) adults with chronic immune (idiopathic) thrombocytopenic purpura (ITP). *Romiplostim was also significantly more effective than placebo with regard to a number of secondary endpoints, including the proportions of patients with an overall (durable plus transient) platelet response or who required ITP rescue medications. The majority of romiplostim-treated patients receiving concurrent ITP drugs were able to reduce or discontinue these therapies. *Platelet response was maintained by most patients during longer-term treatment with romiplostim for up to 3 or 4 years in an open-label extension study. *Romiplostim was generally well tolerated. Almost all adverse events in the phase III studies were of mild-to-moderate intensity; most were unrelated to treatment. Longer-term treatment with romiplostim had an adverse event profile consistent with that observed in the phase III studies.

Publication types

  • Review

MeSH terms

  • Carrier Proteins* / pharmacokinetics
  • Carrier Proteins* / pharmacology
  • Carrier Proteins* / therapeutic use
  • Chronic Disease
  • Clinical Trials, Phase III as Topic
  • Humans
  • Infusions, Subcutaneous
  • Purpura, Thrombocytopenic, Idiopathic / drug therapy*
  • Receptors, Fc* / therapeutic use
  • Recombinant Fusion Proteins* / pharmacokinetics
  • Recombinant Fusion Proteins* / pharmacology
  • Recombinant Fusion Proteins* / therapeutic use
  • Thrombopoietin


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