title: Remission and platelet responses with romiplostim in primary immune thrombocytopenia: final results from a phase 2 study.
abstract: In anecdotal reports, some patients with immune thrombocytopenia (ITP) maintained platelet counts after discontinuing romiplostim. Here, we examined rates of platelet response (≥50 × 10(9) /l), remission, splenectomy and adverse events in patients with primary ITP duration ≤6 months who were treated with romiplostim for ≤12 months. The starting dose of romiplostim was 1 μg/kg; concomitant and rescue treatments were permitted to maintain platelet counts. Patients with platelet counts ≥50 × 10(9) /l at the end of 12 months entered a dose taper in which the romiplostim dose was decreased as long as platelet counts were maintained. Remission (platelet count ≥50 × 10(9) /l for 24 consecutive weeks with no ITP treatments) was evaluated in patients once romiplostim was discontinued. Over the 12 months, a high response rate (>90%) was observed. Platelet response occurred quickly (median, ~2 weeks) and was observed for a cumulative median of 11 months. Remission was observed in 24 patients (32%); there were no significantly predictors of remission. Most (20/24) patients had remission start before the forced taper. No new safety signals were identified. Thus, in patients with early-stage ITP, romiplostim was well tolerated and induced rapid responses, with remission occurring in approximately one-third of patients (NCT01143038, Amgen 20080435).
authors.affiliation: The Pathology Clinical Academic Group, Pathology Clinical Academic Unit, Pathology and Pharmacy Building, The Royal London Hospital, London, UK.
authors.forename: Adrian
authors.initials: A
authors.lastname: Newland
authors.affiliation: Department of Internal Medicine, Centre Hospitalier Universitaire (CHU) Henri-Mondor, INSERM U955, Créteil Cedex, France.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Godeau
authors.affiliation: The Center for Cancer and Blood Disorders, Bethesda, MD, USA.
authors.forename: Victor
authors.initials: V
authors.lastname: Priego
authors.affiliation: Universite Victor Segalen Bordeaux, Pessac Cedex, France.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Viallard
authors.affiliation: C.Hospitalario Universitario A Coruña-INIBIC, Laboratorio de Hematología,Carretera de las Jubias, Galicia, Spain.
authors.forename: María F
authors.initials: MF
authors.lastname: López Fernández
authors.affiliation: Amgen Inc., Morganville, NJ, USA.
authors.forename: Amelia
authors.initials: A
authors.lastname: Orejudos
authors.affiliation: Amgen Inc., Thousand Oaks, CA, USA.
authors.forename: Melissa
authors.initials: M
authors.lastname: Eisen
mesh_terms: D000328:Adult; D001327:Autoimmune Diseases / Q000097:blood / Q000188:drug therapy*; D001792:Blood Platelets / Q000187:drug effects; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D011446:Prospective Studies; D011961:Receptors, Fc / Q000008:administration & dosage / Q000627:therapeutic use*; D053628:Receptors, Thrombopoietin / Q000819:agonists; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D012074:Remission Induction; D013921:Thrombocytopenia / Q000097:blood / Q000188:drug therapy*; D013926:Thrombopoietin / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D011961:Receptors, Fc; D053628:Receptors, Thrombopoietin; D011993:Recombinant Fusion Proteins; D013926:Thrombopoietin; C488777:romiplostim
keywords: immune thrombocytopenia; platelet response; remission; romiplostim; thrombopoietin receptor agonist