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Rabbit Antithymocyte Globulin Versus Campath-1H for Treating Severe Aplastic Anemia

Phase 2
Completed
Conditions
Aplastic Anemia
Interventions
Registration Number
NCT00065260
Lead Sponsor
National Heart, Lung, and Blood Institute (NHLBI)
Brief Summary

Severe aplastic anemia, characterized by pancytopenia and a hypocellular bone marrow, is effectively treated by immunosuppressive therapy, usually a combination of antithymocyte globulin (ATG) and cyclosporine (CsA). Survival rates following this regimen are equivalent to those achieved with allogeneic stem cells transplantation. However, approximately 1/3 of patients will not show blood count improvement after ATG/CsA. General experience and small pilot studies have suggested that such patients may benefit from further immunosuppression. Furthermore, analysis of our own clinical data suggest that patients with poor blood count responses to a single course of ATG, even when transfusion-independence is achieved, have a markedly worse prognosis than patients with robust hematologic improvement. The management of such cases is uncertain.

This study will enroll patients who are either refractory to h-ATG (continued severe pancytopenia) or who have only modest improvement in blood counts (weak hematologic responders) to receive a further immunosuppressive therapy, delivered either as rabbit ATG (Thymoglobulin, r-ATG) or a humanized monoclonal antibody to T-cells, alemtuzumab (Campath-1H ). Primary endpoint will be response rate at 3 months defined as no longer meeting criteria for severe aplastic anemia. Relapse, robustness of hematopoietic recovery at 3 months, survival and clonal evolution to paroxysmal nocturnal hemoglobinuria (PNH), myelodysplasia and acute leukemia will be the secondary endpoints.

Detailed Description

Severe aplastic anemia, characterized by pancytopenia and a hypocellular bone marrow, is effectively treated by immunosuppressive therapy, usually a combination of antithymocyte globulin (ATG) and cyclosporine (CsA). Survival rates following this regimen are equivalent to those achieved with allogeneic stem cells transplantation. However, approximately 1/3 of patients will not show blood count improvement after ATG/CsA. General experience and small pilot studies have suggested that such patients may benefit from further immunosuppression. Furthermore, analysis of our own clinical data suggest that patients with poor blood count responses to a single course of ATG, even when transfusion-independence is achieved, have a markedly worse prognosis than patients with robust hematologic improvement. The management of such cases is uncertain.

This study will enroll patients who are either refractory to h-ATG (continued severe pancytopenia) or who have only modest improvement in blood counts (weak hematologic responders) to receive further immunosuppressive therapy, delivered either as rabbit ATG (Thymoglobulin , r-ATG) or a humanized monoclonal antibody to T-cells, alemtuzumab (Campath-1H ). Primary endpoint will be response rate at 6 months defined as no longer meeting criteria for severe aplastic anemia. Relapse, robustness of hematopoietic recovery at 6 months, survival and clonal evolution to paroxysmal nocturnal hemoglobinuria (PNH), myelodysplasia and acute leukemia will be the secondary endpoints.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
54
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
r-ATG /cyclosporiner-ATGA randomized trial of rabbit anti-thymocyte globulin (r-ATG)/ cyclosporine (CsA) versus Campath-1H in aplastic anemia patients with refractory pancytopenia or suboptimal hematological response after horse ATG treatment. Subjects who receive rabbit ATG/ CsA will be given rabbit ATG 3.5mg/kg/day for 5 days and CsA 10mg/kg/day orally twice daily for 6 months (15mg/kg/day for children under 12 yrs. Subjects who receive Campath-1H will receive an intravenous infusion for 10 days. Adult subjects will receive 10mg/day (children:0.2mg/kg/day).
Alemtuzumab (Campath-1H)Campath-1HA randomized trial of rabbit anti-thymocyte globulin (ATG)/ cyclosporine (CsA) versus Campath-1H in aplastic anemia patients with refractory pancytopenia or suboptimal hematological response after horse ATG treatment. Subjects who receive rabbit ATG/ CsA will be given rabbit ATG 3.5mg/kg/day for 5 days and CsA 10mg/kg/day orally twice daily for 6 months (15mg/kg/day for children under 12 yrs. Subjects who receive Campath-1H will receive an intravenous infusion for 10 days. Adult subjects will receive 10mg/day (children:0.2mg/kg/day).
r-ATG /cyclosporineCsAA randomized trial of rabbit anti-thymocyte globulin (r-ATG)/ cyclosporine (CsA) versus Campath-1H in aplastic anemia patients with refractory pancytopenia or suboptimal hematological response after horse ATG treatment. Subjects who receive rabbit ATG/ CsA will be given rabbit ATG 3.5mg/kg/day for 5 days and CsA 10mg/kg/day orally twice daily for 6 months (15mg/kg/day for children under 12 yrs. Subjects who receive Campath-1H will receive an intravenous infusion for 10 days. Adult subjects will receive 10mg/day (children:0.2mg/kg/day).
Primary Outcome Measures
NameTimeMethod
Participants no Longer Meeting Criteria for Severe Aplastic Anemia.6 months

Number of participants no longer meeting the criteria for severe aplastic anemia as measured by response to treatment at 6 months

Secondary Outcome Measures
NameTimeMethod
Number of Participants With Robust Hematologic Recovery With Reticulocyte or Platelet Count6 months

Number of participants with robust hematologic recovery with reticulocyte or platelet count ≥ 50,000/uL

Percentage of Cumulative Incidence of Relapse in Participants3 year

Percentage of cumulative incidence of relapse of disease in participants

Percentage of Cumulative Incidence of Clonal Evolution in Participants3 years

Percent of cumulative incidence of clonal evolution in participants to either paroxysmal nocturnal hemoglobinuria (PNH), myelodysplasia or acute leukemia.

Percentage of Participants no Longer Meeting Criteria for Severe Aplastic Anemia.3 months and 6 months

Percentage of participants no longer meeting the criteria for severe aplastic anemia as measured by response to treatment

Trial Locations

Locations (1)

National Institutes of Health Clinical Center, 9000 Rockville Pike

🇺🇸

Bethesda, Maryland, United States

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