Company:

Amgen

Thrombopoietin receptor agonist

Romiplostim (recombinant) 250mcg, 500mcg; per vial; lyophilized pwd for SC inj after reconstitution; contains sucrose and mannitol; preservative-free.

Thrombocytopenia in patients with chronic immune (idiopathic) thrombocytopenic purpura (ITP) who have had an insufficient response to corticosteroids, immunoglobulins, or splenectomy.

Nplate is a member of the thrombopoietin (TPO) mimetic class. It is an Fc-peptide fusion protein that activates intracellular transcriptional pathways leading to increased platelet production via the TPO receptor. Nplate produces dose-dependent increases in platelet production by binding and activating the TPO receptor in a mechanism similar to endogenous TPO.

The safety and efficacy of Nplate was evaluated in 2 open-label, placebo-controlled clinical trials of chronic ITP patients with or without splenectomies and platelet counts ≤30x10⁹/L. Patients in both studies received weekly SC injections individually adjusted to maintain platelet counts between 50 to 200x10⁹/L.

Splenectomized patients achieved an overall platelet response of 79% versus 0%, when compared to placebo. Non-splenectomized patients achieved an overall platelet response of 88% versus 14%, when compared to placebo. A reduction or discontinuation of baseline concurrent ITP treatments were also seen in both groups compared to placebo.

Give by SC inj. To reduce risk of bleeding: use lowest effective dose to achieve and maintain platelets ≥50x10⁹/L. ≥18yrs: initially: 1mcg/kg weekly; may increase by 1mcg/kg if platelets <50x10⁹/L; max: 10mcg/kg weekly. May reduce by 1mcg/kg if platelets >200x10⁹/L for 2 consecutive weeks. Do not dose if platelets >400x10⁹/L; resume Nplate at a dose reduced by 1mcg/kg when platelets fallen to <200x10⁹/L. Discontinue if platelets has not increased after 4 weeks at max dose.

<18yrs: not recommended.

Not for normalization of platelet counts. Risk of bone marrow fibrosis with cytopenias. Worsened thrombocytopenia after discontinuation. Monitor CBCs, platelets, and peripheral blood smears before and weekly during dose adjustments then monthly after achieving stable dose; and weekly for 2 weeks after discontinuation of therapy. Monitor after initial response for formation of neutralizing antibodies. Risk of hematologic malignancies (esp. myelodysplastic syndrome). Renal or hepatic impairment. Elderly. Pregnancy (Cat.C). Nursing mothers.

May increase bleeding risk with anticoagulants or antiplatelet agents.

Arthralgia, dizziness, insomnia, myalgia, pain in extremity, abdominal pain, shoulder pain, dyspepsia, paresthesia, headaches; bone marrow reticulin deposition, worsening thrombocytopenia, risk of bleeding, thrombotic/thromboembolic complications, antibody formation.

Available only through Nplate NEXUS program. To register for Nplate NEXUS program or for pregnancy registry call Amgen at (877) Nplate1.

Single-use vials—1

10/10/08