Anti-thymocyte Globulin and Cyclosporine as First-Line Therapy in Treating Patients With Severe Aplastic Anemia

Phase 2

Completed

Brief Summary: RATIONALE: Immunosuppressive therapies, such as anti-thymocyte globulin and cyclosporine, may improve bone marrow function and increase blood cell counts. PURPOSE: This phase II trial is studying how well giving anti-thymocyte globulin together with cyclosporine as first-line therapy works in treating patients with severe aplastic anemia.

Detailed Description: PRIMARY OBJECTIVES: To determine the response rate of r-ATG and CsA in the first line setting. SECONDARY OBJECTIVES: To determine the level of IS as assessed by Immuknow assay in responders and compare it to non-responders. OUTLINE:Patients receive anti-thymocyte globulin IV over 4-24 hours daily on days 1-5. Beginning on day 6, patients receive oral cyclosporine twice daily for 6 months followed by a taper. Treatment continues in the absence of disease progression or unacceptable toxicity.

Recruitment & Eligibility

Inclusion Criteria

All patients with sAA as defined by Camitta who are candidates for IS therapy; these criteria include bone marrow cellularity < 25% or 25-50% with < 30% of hematopoietic cells; it should also have two of the following three parameters: peripheral blood neutrophils < 0.5 x 10^9/L, platelets < 20 x 10^9/L and reticulocytes < 60 x 10^9/L in anemic patients
If cytogenetic testing has been done, it should show normal karyotype or be not informative
Patients should be either unwilling or otherwise ineligible (age, comorbidities, lack of donor) for bone marrow transplantation as a therapeutic modality
Not previously treated with ATG for sAA
Patients must have ECOG performance status of 0, 1, or 2
Vitamin B12 and folic acid deficiency must be ruled out by measurement of serum levels
Patients must have had a bone marrow biopsy examination in the three months prior to enrolling in the study
Must be able to provide informed consent
Systemic and other hematologic causes of pancytopenia, based on clinical presentation, must have been ruled out

Exclusion Criteria

Patients with clinically evident congestive heart failure, serious cardiac arrhythmias; symptoms of coronary artery disease must be cleared by cardiology prior to therapy
Patients who have had chemotherapy, radiotherapy, or immunotherapy or other investigational drug use within 3 weeks prior to study entry
Pregnant women
All females of childbearing potential must have a blood test or urine study within two weeks prior to induction registration to rule out pregnancy
Women of childbearing potential are strongly advised to use an accepted and effective method of contraception
Patients who have medical, psychological, or social conditions that may interfere with the patient's participation in the study or evaluation of the study results

Arm && Interventions

Group	Intervention	Description
rATG + Cyclosporine	anti-thymocyte globulin	Patients receive anti-thymocyte globulin IV daily over 4-24 hours on days 1-5. Beginning on day 6, patients receive oral cyclosporine twice daily for 6 months followed by a taper. Treatment continues in the absence of disease progression or unacceptable toxicity
rATG + Cyclosporine	cyclosporine	Patients receive anti-thymocyte globulin IV daily over 4-24 hours on days 1-5. Beginning on day 6, patients receive oral cyclosporine twice daily for 6 months followed by a taper. Treatment continues in the absence of disease progression or unacceptable toxicity

Primary Outcome Measures

Name	Time	Method
Patients Treated With Rabbit Antithymocyte Globulin (r-ATG/Thymoglobulin) and Cyclosporine (CsA) Achieving at Least a Partial Remission (PR) at 6 Months	At 6 months	Patients will be classified as responders if they have transfusion independence and meet two of the following three criteria: ANC greater than 500/mm3; platelet count greater than 20,000/mm3; and reticulocyte count greater than 40,000/mm3. Transfusion independence is defined as no need for transfusions for one month prior to response assessment.

Secondary Outcome Measures