title: Effect of a thrombopoietin receptor agonist on use of intravenous immune globulin in patients with immune thrombocytopenia.
abstract: BACKGROUND
  Thrombopoietin receptor agonists are new treatments for patients with chronic immune thrombocytopenia (ITP). How one of these agent, romiplostim, has impacted practice patterns, especially the use of intravenous immune globulin (IVIG), has not been evaluated outside of clinical trials.
  
  
  METHODS
  This was a retrospective cohort study of adult ITP patients treated with romiplostim in four Canadian centers. Patients had primary or secondary ITP and were followed for 1 year before starting weekly romiplostim treatment. We compared IVIG use, clinical outcomes, and cost before and after romiplostim.
  
  
  RESULTS
  Twenty-nine patients with ITP received romiplostim. Median age was 54 years (interquartile range [IQR], 45-63 years) and patients had a median of two prior ITP treatments (IQR, 1-4) including splenectomy (n = 7). Median platelet (PLT) count was 23 × 10(9) before and 124 × 10(9) after romiplostim. Median duration of romiplostim treatment was 3.7 months. Patients used a median of two IVIG infusions per year before and 0.7 per year after starting romiplostim (p = 0.16). For patients who received weekly romiplostim for at least 1 month (n = 19), IVIG infusions were three (IQR, 1-5) per year before and 0.7 (IQR, 0.4-1.6) per year after romiplostim. Results were squewed by two high IVIG users. Nineteen (66%) patients discontinued romiplostim treatment during follow-up because of lack of response (n = 8), sustained response (n = 5), toxicities (n = 4), or response to splenectomy (n = 2). Overall health care costs were similar before and after romiplostim when concomitant treatments, nursing resources, and hospitalizations were considered.
  
  
  CONCLUSIONS
  Romiplostim was associated with improved PLT counts and fewer IVIG infusions for most ITP patients. In practice, romiplostim was generally not continued long term and was cost neutral for overall ITP management.
authors.affiliation: Department of Medicine Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario.|Canadian Blood Services.
authors.forename: Michelle P
authors.initials: MP
authors.lastname: Zeller
authors.affiliation: Department of Medicine Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario.|McMaster Transfusion Research Program, Hamilton, Ontario, Canada.
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Heddle
authors.affiliation: Department of Medicine Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario.
authors.forename: John G
authors.initials: JG
authors.lastname: Kelton
authors.affiliation: McMaster Transfusion Research Program, Hamilton, Ontario, Canada.
authors.forename: Korinne
authors.initials: K
authors.lastname: Hamilton
authors.affiliation: McMaster Transfusion Research Program, Hamilton, Ontario, Canada.
authors.forename: Grace
authors.initials: G
authors.lastname: Wang
authors.affiliation: Health Research Methodology, Department of Clinical Epidemiology and Biostatistics, McMaster University.|McMaster Transfusion Research Program, Hamilton, Ontario, Canada.
authors.forename: Naushin
authors.initials: N
authors.lastname: Sholapur
authors.affiliation: McMaster Transfusion Research Program, Hamilton, Ontario, Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: Carruthers
authors.affiliation: Department of Medicine Division of Hematology, London Health Sciences Centre, London, Ontario, Canada.
authors.forename: Cyrus
authors.initials: C
authors.lastname: Hsia
authors.affiliation: Department of Hemato-Oncology, Montreal University, Montreal, Quebec, Canada.
authors.forename: Normand
authors.initials: N
authors.lastname: Blais
authors.affiliation: Department of Medicine Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario.
authors.forename: Lisa
authors.initials: L
authors.lastname: Toltl
authors.affiliation: Windsor Regional Cancer Program, Windsor Regional Hospital, Windsor, Ontario, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Hamm
authors.affiliation: Department of Hemato-Oncology, Montreal University, Montreal, Quebec, Canada.
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Pearson
authors.affiliation: Department of Medicine Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario.|Canadian Blood Services.
authors.forename: Donald M
authors.initials: DM
authors.lastname: Arnold
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016756:Immunoglobulins, Intravenous / Q000627:therapeutic use*; D007155:Immunologic Factors / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D016553:Purpura, Thrombocytopenic, Idiopathic / Q000188:drug therapy*; D011961:Receptors, Fc / Q000627:therapeutic use*; D053628:Receptors, Thrombopoietin / Q000819:agonists*; D011993:Recombinant Fusion Proteins / Q000627:therapeutic use*; D012189:Retrospective Studies; D013926:Thrombopoietin / Q000627:therapeutic use*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D016756:Immunoglobulins, Intravenous; D007155:Immunologic Factors; D011961:Receptors, Fc; D053628:Receptors, Thrombopoietin; D011993:Recombinant Fusion Proteins; C082218:MPL protein, human; D013926:Thrombopoietin; C488777:romiplostim