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

Aplastic Anemia Clinical Trial

Official title:

A Randomized Trial of Immunosuppression in Aplastic Anemia Patients With Refractory Pancytopenia or Suboptimal Hematologic Response After h-ATG/CsA Treatment

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00065260
• Other study ID #: 030249
• Secondary ID: 03-H-0249
• Status: Completed
• Phase: Phase 2
• Start date: November 6, 2003
• Est. completion date: February 5, 2016

Study information

• Verified date: June 2021
• Source: National Institutes of Health Clinical Center (CC)
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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 information / eligibility

• Status: Completed
• Enrollment: 54
• Est. completion date: February 5, 2016
• Est. primary completion date: December 29, 2010
• Accepts healthy volunteers: No
• Gender: All
• Age group: 2 Years and older

Eligibility

• INCLUSION CRITERIA:

Severe aplastic anemia confirmed at NIH by:

Bone marrow cellularity less than 30% (excluding lymphocytes) At least two of the following: Absolute neutrophil count less than 500/microL; Platelet count less than 20,000/ microL; Reticulocyte count less than 60,000/ microL. Severe aplastic anemia refractory to prior course(s) of h-ATG/CsA defined after 3 months from treatment with less or equal to 4 years from receiving h-ATG. OR Suboptimal response to initial immunosuppression with h-ATG/CsA as defined by platelet and reticulocyte count less than 50,000 /microL at 3 months. Age greater than or equal to 2 years of age EXCLUSION CRITERIA: Diagnosis of Fanconi anemia. Evidence of a clonal disorder on cytogenetics. Patients with super severe neutropenia (ANC less than 200/microL) will not be excluded initially if results of cytogenetics are not available or pending. If evidence of a clonal disorder is later identified, the subject will go off study. Prior treatment courses with rabbit ATG or high dose cyclophosphamide (200 mg/kg or equivalent). Infection not adequately responding to appropriate therapy. Underlying immunodeficiency state including seropositivity for HIV. Failure to discontinue the herbal supplements Echinacea purpurea or Usnea barbata (Old Man's Beard) within two weeks of enrollment. Previous hypersensitivity to Campath-1H or its components. Moribund status or concurrent hepatic, renal, cardiac, neurologic, pulmonary, infectious, or metabolic disease of such severity that it would preclude the patient s ability to tolerate protocol therapy or that death within 7-10 days is likely. Potential subjects with cancer who are on active chemotherapeutic treatment or who take drugs with hematological effects will not be eligible. Serum creatinine greater than 2.5 mg/dL. Current pregnancy or lactation or unwillingness to take contraceptives. Inability to understand the investigational nature of the study or give informed consent.

Related Conditions & MeSH terms

• Anemia
• Anemia, Aplastic
• Aplastic Anemia

Intervention

Drug:
• Campath-1H
Campath-1H IV 10 days. Adults:10mg/day (children:0.2mg/kg/day).
• r-ATG
Rabbit ATG 3.5mg/kg/day for consecutive 5 days
• CsA
CsA 10mg/kg/day orally twice daily for 6 months (15mg/kg/day for children under 12 yrs.

Locations

Country	Name	City	State
United States	National Institutes of Health Clinical Center, 9000 Rockville Pike	Bethesda	Maryland

Sponsors (1)

Lead Sponsor	Collaborator
National Heart, Lung, and Blood Institute (NHLBI)

Country where clinical trial is conducted

United States, 

References & Publications (3)

Mathé G, Amiel JL, Schwarzenberg L, Choay J, Trolard P, Schneider M, Hayat M, Schlumberger JR, Jasmin C. Bone marrow graft in man after conditioning by antilymphocytic serum. Br Med J. 1970 Apr 18;2(5702):131-6. — View Citation

Stein RS, Means RT Jr, Krantz SB, Flexner JM, Greer JP. Treatment of aplastic anemia with an investigational antilymphocyte serum prepared in rabbits. Am J Med Sci. 1994 Dec;308(6):338-43. — View Citation

Young NS, Maciejewski J. The pathophysiology of acquired aplastic anemia. N Engl J Med. 1997 May 8;336(19):1365-72. Review. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Participants no Longer Meeting Criteria for Severe Aplastic Anemia.	Number of participants no longer meeting the criteria for severe aplastic anemia as measured by response to treatment at 6 months	6 months
Secondary	Number of Participants With Robust Hematologic Recovery With Reticulocyte or Platelet Count	Number of participants with robust hematologic recovery with reticulocyte or platelet count = 50,000/uL	6 months
Secondary	Percentage of Cumulative Incidence of Relapse in Participants	Percentage of cumulative incidence of relapse of disease in participants	3 year
Secondary	Percentage of Cumulative Incidence of Clonal Evolution in Participants	Percent of cumulative incidence of clonal evolution in participants to either paroxysmal nocturnal hemoglobinuria (PNH), myelodysplasia or acute leukemia.	3 years
Secondary	Percentage of Participants no Longer Meeting Criteria for Severe Aplastic Anemia.	Percentage of participants no longer meeting the criteria for severe aplastic anemia as measured by response to treatment	3 months and 6 months

External Links

•   NIH Clinical Center Detailed Web Page