Three Immunosuppressive Treatment Regimens for Severe Aplastic Anemia

Summary

Severe aplastic anemia (SAA) is a life-threatening bone marrow failure disorder characterized by pancytopenia and a hypocellular bone marrow. Allogeneic bone marrow transplantation offers the opportunity for cure in 70% of patients, but most patients are not suitable candidates for hematopoietic stem cell transplantation (HSCT) due to advanced age or lack of a histocompatible donor. For these patients, comparable long term survival is attainable with immunosuppressive treatment with anti-thymocyte globulin (ATG) and cyclosporine (CsA). However, of those patients treated with horse ATG(h-ATG)/CsA, one quarter to one third will not respond, and about 50% of responders relapse. Auto-reactive T cells may be resistant to the effect of ATG/CsA (non-responders), while in others residual auto-reactive T cells expand post-treatment, leading to hematopoietic stem cell destruction and recurrent pancytopenia (relapse). As long term survival is correlated to response rates and robustness of hematopoietic recovery, novel immunosuppressive regimens that can achieve hematologic response and decrease relapse rates are needed. This trial will compare the effectiveness of three immunosuppressive regimens as first line therapies in patients with SAA with early hematologic response as the primary endpoint, as well as assess the role of extended CsA treatment after h-ATG in reducing numbers of late events of relapse and clonal evolution. Randomization is employed to obtain an equal distribution of subject to each arm; comparisons of early hematologic responses will be made among the rates observed among the three concurrent arms (rabbit-ATG \[r-ATG\] versus standard h-ATG; alemtuzumab vs standard h-ATG). For long course CSA, comparison of primary end points will be to well established historic relapse rate of 38% at 2-3 years and a cumulative rate of clonal evolution of 15%.

Timeline

Start

2005-11-28

Primary completion

2016-05-04

Completion

2016-05-04

Publications

• Background Young NS, Barrett AJ. The treatment of severe acquired aplastic anemia. Blood. 1995 Jun 15;85(12):3367-77. No abstract available.
• Background Young NS, Maciejewski J. The pathophysiology of acquired aplastic anemia. N Engl J Med. 1997 May 8;336(19):1365-72. doi: 10.1056/NEJM199705083361906. No abstract available.
• Background Zoumbos NC, Gascon P, Djeu JY, Trost SR, Young NS. Circulating activated suppressor T lymphocytes in aplastic anemia. N Engl J Med. 1985 Jan 31;312(5):257-65. doi: 10.1056/NEJM198501313120501.
• Background Feng X, Scheinberg P, Biancotto A, Rios O, Donaldson S, Wu C, Zheng H, Sato K, Townsley DM, McCoy JP, Young NS. In vivo effects of horse and rabbit antithymocyte globulin in patients with severe aplastic anemia. Haematologica. 2014 Sep;99(9):1433-40. doi: 10.3324/haematol.2014.106542. Epub 2014 Jun 6.
• Background Scheinberg P, Townsley D, Dumitriu B, Scheinberg P, Weinstein B, Rios O, Wu CO, Young NS. Horse antithymocyte globulin as salvage therapy after rabbit antithymocyte globulin for severe aplastic anemia. Am J Hematol. 2014 May;89(5):467-9. doi: 10.1002/ajh.23669. Epub 2014 Mar 7.
• Background Scheinberg P, Nunez O, Weinstein B, Scheinberg P, Wu CO, Young NS. Activity of alemtuzumab monotherapy in treatment-naive, relapsed, and refractory severe acquired aplastic anemia. Blood. 2012 Jan 12;119(2):345-54. doi: 10.1182/blood-2011-05-352328. Epub 2011 Nov 8.
• Background Scheinberg P, Nunez O, Weinstein B, Scheinberg P, Biancotto A, Wu CO, Young NS. Horse versus rabbit antithymocyte globulin in acquired aplastic anemia. N Engl J Med. 2011 Aug 4;365(5):430-8. doi: 10.1056/NEJMoa1103975.
• Zaimoku Y, Patel BA, Adams SD, Shalhoub R, Groarke EM, Lee AAC, Kajigaya S, Feng X, Rios OJ, Eager H, Alemu L, Quinones Raffo D, Wu CO, Flegel WA, Young NS. HLA associations, somatic loss of HLA expression, and clinical outcomes in immune aplastic anemia. Blood. 2021 Dec 30;138(26):2799-2809. doi: 10.1182/blood.2021012895.
• Giudice V, Wu Z, Kajigaya S, Fernandez Ibanez MDP, Rios O, Cheung F, Ito S, Young NS. Circulating S100A8 and S100A9 protein levels in plasma of patients with acquired aplastic anemia and myelodysplastic syndromes. Cytokine. 2019 Jan;113:462-465. doi: 10.1016/j.cyto.2018.06.025. Epub 2018 Jun 27.
• Giudice V, Banaszak LG, Gutierrez-Rodrigues F, Kajigaya S, Panjwani R, Ibanez MDPF, Rios O, Bleck CK, Stempinski ES, Raffo DQ, Townsley DM, Young NS. Circulating exosomal microRNAs in acquired aplastic anemia and myelodysplastic syndromes. Haematologica. 2018 Jul;103(7):1150-1159. doi: 10.3324/haematol.2017.182824. Epub 2018 Apr 19.
• Hosokawa K, Kajigaya S, Feng X, Desierto MJ, Fernandez Ibanez MD, Rios O, Weinstein B, Scheinberg P, Townsley DM, Young NS. A plasma microRNA signature as a biomarker for acquired aplastic anemia. Haematologica. 2017 Jan;102(1):69-78. doi: 10.3324/haematol.2016.151076. Epub 2016 Sep 22.

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