title: Safety and efficacy of romiplostim in patients with lower-risk myelodysplastic syndrome and thrombocytopenia.
abstract: OBJECTIVE
  To assess the safety and efficacy of romiplostim, a peptibody that increases platelet production, for treatment of thrombocytopenic patients with myelodysplastic syndromes (MDS).
  
  
  METHODS
  Eligible patients had lower-risk MDS (International Prognostic Scoring System low or intermediate 1), a mean baseline platelet count <or= 50 x 10(9)/L, and were only receiving supportive care. Patients received three injections of 300, 700, 1,000, or 1,500 microg romiplostim at weekly intervals. After evaluation of platelet response at week 4, patients could continue to receive romiplostim in a treatment extension phase for up to 1 year.
  
  
  RESULTS
  All 44 patients who enrolled completed the treatment phase; 41 patients continued into the extension phase. Median platelet counts increased throughout the study, from fewer than 30 x 10(9)/L at baseline to 60, 73, 38, and 58 x 10(9)/L at week 4 for the 300-, 700-, 1,000-, and 1,500 -microg dose cohorts, respectively. A durable platelet response (per International Working Group 2000 criteria for 8 consecutive weeks independent of platelet transfusions) was achieved by 19 patients (46%). The incidence of bleeding events and platelet transfusions was less common among patients who achieved a durable platelet response than those who did not (4.3 v 39.3 per 100 patient-weeks). Forty-three patients (98%) reported one or more adverse events. Treatment-related serious adverse events were reported in five patients (11%), all of whom were in the 1,500-microg dose cohort. Two patients progressed to acute myeloid leukemia during the study. No neutralizing antibodies to either romiplostim or endogenous thrombopoietin were seen.
  
  
  CONCLUSIONS
  Romiplostim appeared well-tolerated in this study and may be a useful treatment for patients with MDS and thrombocytopenia.
authors.affiliation: Leukemia Department, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Box 428, Houston, TX 77030, USA. hkantarj@mdanderson.org
authors.forename: Hagop
authors.initials: H
authors.lastname: Kantarjian
authors.forename: Pierre
authors.initials: P
authors.lastname: Fenaux
authors.forename: Mikkael A
authors.initials: MA
authors.lastname: Sekeres
authors.forename: Pamela S
authors.initials: PS
authors.lastname: Becker
authors.forename: Adam
authors.initials: A
authors.lastname: Boruchov
authors.forename: David
authors.initials: D
authors.lastname: Bowen
authors.forename: Eva
authors.initials: E
authors.lastname: Hellstrom-Lindberg
authors.forename: Richard A
authors.initials: RA
authors.lastname: Larson
authors.forename: Roger M
authors.initials: RM
authors.lastname: Lyons
authors.forename: Petra
authors.initials: P
authors.lastname: Muus
authors.forename: Jamile
authors.initials: J
authors.lastname: Shammo
authors.forename: Robert
authors.initials: R
authors.lastname: Siegel
authors.forename: Kuolung
authors.initials: K
authors.lastname: Hu
authors.forename: Janet
authors.initials: J
authors.lastname: Franklin
authors.forename: Dietmar P
authors.initials: DP
authors.lastname: Berger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006401:Hematologic Agents / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009190:Myelodysplastic Syndromes / Q000150:complications / Q000188:drug therapy*; D011961:Receptors, Fc / Q000627:therapeutic use*; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use*; D013921:Thrombocytopenia / Q000188:drug therapy* / Q000209:etiology; D013926:Thrombopoietin / Q000627:therapeutic use*; D016896:Treatment Outcome
chemical_list: D006401:Hematologic Agents; D011961:Receptors, Fc; D011993:Recombinant Fusion Proteins; D013926:Thrombopoietin; C488777:romiplostim