title: Efficacy of rabbit anti-thymocyte globulin in severe aplastic anemia.
abstract: BACKGROUND
  A combination of horse anti-thymocyte globulin and cyclosporine produces responses in 60-70% of patients with severe aplastic anemia. We performed a phase II study of rabbit anti-thymocyte globulin and cyclosporine as first-line therapy for severe aplastic anemia.
  
  
  METHODS
  Twenty patients with severe aplastic anemia treated with rabbit anti-thymocyte globulin were compared to 67 historical control cases with matched clinical characteristics treated with horse anti-thymocyte globulin.
  
  
  RESULTS
  Response rates at 3, 6 and 12 months were similar for patients treated with rabbit anti-thymocyte globulin or horse anti-thymocyte globulin: 40% versus 55% (P=0.43), 45% versus 58% (P=0.44) and 50% versus 58% (P=0.61), respectively. No differences in early mortality rates or overall survival were observed. We then performed multivariable analyses of response at 6 months and overall survival and identified the presence of a paroxysmal nocturnal hemoglobinuria clone (P=0.01) and a pretreatment absolute reticulocyte count greater than 30×10(9)/L (P=0.007) as independent predictors of response and younger age (P=0.003), higher pretreatment absolute neutrophil (P=0.02) and absolute lymphocyte counts (P=0.03) as independent predictors of overall survival. None of the immunogenetic polymorphisms studied was predictive of response to immunosupressive therapy.
  
  
  CONCLUSIONS
  Despite reports suggesting differences in biological activity of different anti-thymocyte globulin preparations, rabbit and horse anti-thymocyte globulin appear to have a similar efficacy for up-front treatment of severe aplastic anemia. Clinicaltrial.gov: NCT01231841).
authors: Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA.
authors: Manuel G
authors: MG
authors: Afable
authors: Mohammed
authors: M
authors: Shaik
authors: Yuka
authors: Y
authors: Sugimoto
authors: Paul
authors: P
authors: Elson
authors: Michael
authors: M
authors: Clemente
authors: Hideki
authors: H
authors: Makishima
authors: Mikkael A
authors: MA
authors: Sekeres
authors: Alan
authors: A
authors: Lichtin
authors: Anjali
authors: A
authors: Advani
authors: Matt
authors: M
authors: Kalaycio
authors: Ramon V
authors: RV
authors: Tiu
authors: Christine L
authors: CL
authors: O'Keefe
authors: Jaroslaw P
authors: JP
authors: Maciejewski
references: Ann Hematol. 2010 Sep;89(9):851-9
references: 20373101
references: Blood. 2002 Sep 1;100(5):1570-4
references: 12176872
references: Blood. 2006 Feb 15;107(4):1308-14
references: 16179371
references: Br J Haematol. 1999 Nov;107(2):330-4
references: 10583220
references: Exp Hematol. 2006 Jul;34(7):826-31
references: 16797409
references: Blood. 2008 Apr 1;111(7):3675-83
references: 18250226
references: Blood. 2003 Feb 15;101(4):1236-42
references: 12393680
references: Leukemia. 2003 Nov;17(11):2101-6
references: 12931212
references: N Engl J Med. 1997 May 8;336(19):1365-72
references: 9134878
references: Haematologica. 2007 Jan;92(1):11-8
references: 17229630
references: Leukemia. 2009 Jul;23(7):1297-302
references: 19242494
references: Haematologica. 2009 Oct;94(10):1407-14
references: 19794084
references: Br J Haematol. 2009 Jan;144(2):206-16
references: 19036108
references: Eur J Haematol. 2010 Feb 1;84(2):154-9
references: 19912311
references: Ann Hematol. 2002 Oct;81(10):566-9
references: 12424537
references: Br J Haematol. 2003 Feb;120(4):679-84
references: 12588356
references: Eur J Immunogenet. 2004 Dec;31(6):267-9
references: 15548264
references: Br J Haematol. 2001 Dec;115(4):1015-22
references: 11843844
references: JAMA. 2003 Mar 5;289(9):1130-5
references: 12622583
references: Blood. 2007 Apr 15;109(8):3219-24
references: 17148582
references: Br J Haematol. 2003 Jul;122(2):289-97
references: 12846899
references: Blood. 2006 Oct 15;108(8):2632-41
references: 16614248
references: Hematol J. 2004;5(3):255-61
references: 15167913
references: Br J Haematol. 2000 Dec;111(4):1164-9
references: 11167757
references: Blood. 1995 Aug 15;86(4):1487-92
references: 7632956
references: Br J Haematol. 1997 Dec;99(3):699-705
references: 9401087
references: Leukemia. 2004 Mar;18(3):460-5
references: 14712285
references: N Engl J Med. 1991 May 9;324(19):1297-304
references: 2017225
references: Blood. 2001 Dec 15;98(13):3513-9
references: 11739151
references: Br J Haematol. 2006 Jun;133(6):622-7
references: 16704436
references: Blood. 2006 Oct 15;108(8):2509-19
references: 16778145
references: J Clin Invest. 2004 Nov;114(9):1209-17
references: 15520849