View clinical trials related to Severe Aplastic Anemia.
Filter by:The primary objective of this study is to assess the safety and efficacy of performing unrelated stem cell transplants using intravenous busulfan and fludarabine as preparative therapy and tacrolimus plus methotrexate as the GVHD prophylaxis regimen. The goal is to demonstrate safety, aiming for a transplant related mortality rate (TRM) of < or equal to 40% at 100 days. A TRM of > or equal to 60% will be considered unacceptable. Another goal is to demonstrate efficacy by showing and overall survival of >40% at 1-year following transplant.
This phase I/II trial studies the side effects of fludarabine phosphate, cyclophosphamide and total-body irradiation followed by donor bone marrow transplant and cyclophosphamide, mycophenolate mofetil, tacrolimus, and sirolimus in treating patients with primary immunodeficiency disorders or noncancerous inherited disorders. Giving low doses of chemotherapy and total-body irradiation before a bone marrow transplant helps prepare the patient's body to accept the incoming donor's bone marrow and decrease the risk that the patient's immune system will reject the donor's stem cells. When the healthy stem cells from a donor are infused into the patient they may help the patient's bone marrow make stem cells, red blood cells, white blood cells, and platelets. Sometimes the transplanted cells from a donor can make an immune response against the body's normal cells called graft versus host disease. Giving cyclophosphamide, mycophenolate mofetil, tacrolimus, and sirolimus after the transplant may help decrease this from happening.
Umbilical cord blood is used as a source of hematopoietic stem cells for bone marrow reconstitution in patients who would be potential candidates for a bone marrow transplant from an unrelated marrow donor. The outcome of transplantation is obtained to assess cord blood myeloid and platelet engraftment, transplant related mortality, overall survival, graft vs. host disease and, for patients with leukemia, lymphoma or myelodysplasia, relapse.
Severe aplastic anemia (SAA) is a life-threatening bone marrow failure disorder characterized by pancytopenia and a hypocellular bone marrow. Allogeneic bone marrow transplantation and immunosuppressive treatment with anti-thymocyte globulin (ATG) and cyclosporine (CsA) have dramatically changed the natural course of this illness, with 5 year survival of 75% in patients undergoing either treatment. Since most patients are not suitable candidates for hematopoietic stem cell transplantation (HSCT) due to advanced age or lack of a histocompatible sibling, efforts at NHLBI have focused on improving immunosuppression treatment in order to improve response rates, survival, and to decrease relapse. In our experience of 122 patients treated at NHLBI with the combination of ATG and cyclosporine, one quarter to one third did not respond; about 50% of responders relapsed; and 5 year survival was correlated with the robustness in blood cell count improvement at 3 months (reticulocyte or platelet count greater than or equal to 50,000 /uL). Why some patients do not respond initially while others relapse is unclear. Autoreactive T cells may be resistant to the effect of ATG/CsA (nonresponders), while in others residual autoreactive T cells expand post-treatment leading to hematopoietic stem cell destruction and recurrent pancytopenia (relapse). Therefore, novel immunosuppressive regimens to increase response rates and hematologic recovery at 3 months and to decrease relapse rates are needed. An ongoing NHLBI trial, which is close to completing accrual, has added mycophenolate mofetil (MMF) for a total of 18 months to standard ATG + CsA in an attempt to reduce the relapse rate after cyclosporine is discontinued. Preliminary results have been disappointing, with no marked reduction in relapse among patients who received MMF. Sirolimus (rapamycin, Rapamune , RAPA) is a novel immunosuppressive agent, which acts synergistically with cyclosporine by blocking T cell activation through CsA-resistant pathways. The potentiation of the combination of CsA-RAPA has been established in vitro and in the clinical setting, mainly in islet cell and solid organ transplantation. The significant increase in response rate seen with the addition of CsA to ATG indicated that an inhibitory effect on T lymphocytes is important in blocking autoreactive T cells in aplastic anemia. The combination of CsA-RAPA may further block activated autoreactive T cells and therefore lead to improved response rates (and survival) and decreased relapse rates. This prospective randomized phase II study will investigate two different immunosuppressive regimens in patients with severe aplastic anemia who have not received prior immunosuppressive therapy. One arm will receive ATG + CsA in addition to sirolimus for 6 months, and the second arm will receive standard ATG + CsA for 6 months followed by a slow taper of CsA with a 25% dose reduction every 3 months for the subsequent 18 months. This trial will determine the effectiveness of sirolimus in patients with aplastic anemia as well as the role of a cyclosporine taper in preventing relapses. Primary endpoint will be no longer meeting criteria for severe aplastic anemia while secondary endpoints are relapse, robustness of hematologic recovery at 3 months, survival, clonal evolution to PNH, myelodysplasia and acute leukemia. 10/11/2005. The Sirolimus (Rapamune) arm of the trial was stopped for lack of efficacy. The study will continue as a single arm study to establish if slow taper of CsA prevents relapse rates after initial standard treatment with ATG followed by CsA for six months.
RATIONALE: Although used primarily to treat malignant disorders of the blood, allogeneic stem cell transplantation can also cure a variety of non-cancerous, inherited or acquired disorders of the blood. Unfortunately, the conventional approach to allogeneic stem cell transplantation is a risky procedure. For some non-cancerous conditions, the risks of this procedure outweigh the potential benefits. This protocol is designed to test a new approach to allogeneic stem cell transplantation. It is hoped that this approach will be better suited for patients with non-cancerous blood and bone marrow disorders.
This study will test the safety and effectiveness of a combination of three drugs in treating severe aplastic anemia and preventing its recurrence. Two drugs used in this trial ATG and cyclosporine are standard combination therapy for aplastic anemia. This study will try to improve this therapy in three ways: 1) by altering the drug regimen to allow the drugs to work better; 2) by reducing the risk of kidney damage; and 3) by adding a third drug mycophenolate mofetil to try to prevent disease relapse. Patients with severe aplastic anemia who do not have a suitable bone marrow donor or who decline bone marrow transplantation may participate in this study. Patients will have a skin test for ATG allergy, chest X-ray, blood test, and bone marrow aspiration before treatment begins. ATG will then be started, infused through a vein continuously for 4 days. Ten days after ATG is stopped, cyclosporine treatment will begin, taken twice a day by mouth in either liquid or capsule form and will continue for 6 months. Also, in the first 2 weeks of treatment, patients will be given a full dose of corticosteroid (prednisone) to prevent serum sickness that could develop as a side effect of ATG therapy. The dosage will be decreased after that. Mycophenolate will be started at the same time as ATG, in two daily doses by mouth, and will continue for 18 months. Patients will be hospitalized at the beginning of the study. During this time, blood will be drawn at 3-week intervals and a bone marrow examination will be repeated 3 months after treatment has begun. Additional tests, including X-rays may be required. After hospital discharge, patients will be followed on an outpatient basis at 3-month intervals. The patients own physician will perform blood tests weekly and kidney and liver function tests every 2 weeks during cyclosporine therapy. Transfusions may be required initially.