4 Clinical Trials for Various Conditions
Background: * Moderate aplastic anemia is a blood disease which may require frequent blood and platelet transfusions. Sometimes patients with this disease can be treated with immunosuppressive drugs. Not all patients respond and not all patients are suitable for this treatment. * Thrombopoietin (TPO) is a protein made by the body. The bone marrow needs TPO to produce platelets. TPO may also be able to stimulate bone marrow stem cells to produce red cells and white cells. However, TPO cannot be given by mouth. This has led researchers to develop the drug eltrombopag, which acts in the same way and can be given by mouth. Eltrombopag has been shown to safely increase platelet numbers in healthy volunteers and in patients with other chronic blood diseases, including severe aplastic anemia. Researchers are interested in looking at whether eltrombopag can be given to people with moderate aplastic anemia and significantly low blood cell counts. Objectives: - To evaluate the safety and effectiveness of eltrombopag in people with moderate aplastic anemia or patients with bone marrow failure and unilineage cytopenia who need treatment for significantly low blood cell counts. Eligibility: - People at least 2 years of age who have moderate aplastic anemia or bone marrow failure and unilineage cytopenia,and significantly low blood cell counts. Design: * Patients will be screened with a physical examination, medical history, blood tests, a bone marrow biopsy, and an eye exam. * Patients will receive eltrombopag by mouth once a day. * Patients will have weekly blood tests to monitor the effectiveness of the treatment and adjust the dose in response to possible side effects. * Patients may continue to take eltrombopag if their platelet count or hemoglobin increases, their requirement for platelet or blood transfusion decreases after 16 to 20 weeks of treatment, and there have been no serious side effects. Access to the drug will continue until the study is closed. Patients will be asked to return for a follow-up visit 6 months after the last dose of medication.
This study will test whether the immune-suppressing drug rituximab can increase blood counts and reduce the need for transfusions in patients with moderate aplastic anemia, pure red cell aplasia, or Diamond Blackfan anemia. These are rare and serious blood disorders in which the immune system turns against bone marrow cells, causing the bone marrow to stop producing red blood cells in patients with pure red cell aplasia and Diamond Blackfan anemia, and red blood cells, white blood cells and platelets in patients with aplastic anemia. Rituximab is a laboratory-made monoclonal antibody that recognizes and destroys white blood cells called lymphocytes that are responsible for destroying bone marrow cells in these diseases. The drug is currently approved by the Food and Drug Administration for treating patients with B-cell non-Hodgkin lymphoma, a disease of white blood cells.
The investigators hypothesis is that eltrombopag given to patients with moderate to very severe aplastic anemia will result in an increase in platelet counts. The investigators hypothesize that in patients with moderate to very severe aplastic anemia, treatment with eltrombopag will lead to fewer platelet transfusions, red blood cell transfusions, and fewer bleeding events. The investigators hypothesize that in patients with moderate to very severe aplastic anemia, eltrombopag will have an acceptable toxicity rate \<3%, at doses that result in increased platelet counts. Finally the investigators hypothesize that plasma eltrombopag levels in peripheral blood will correlate with improved platelet counts.
Aplastic Anemia (AA) is an autoimmune hematologic stem cell disease mediated by activated T-lymphocytes that leads to pancytopenia. The disease related morbidity and mortality if left untreated can approach 90%. For over 30 years, anti-thymocyte globulin (ATG) in combination with cyclosporine (CsA) remains the standard therapy. However, the treatment response with ATG is at best between 50-60% with a sizeable number of partial responses. Treatment with ATG is also associated with significant toxicity and high relapse rate that can be as high as 45%. Since the prognosis in refractory and relapsed AA remains poor, there is a need for less toxic novel immunosuppressive agents that can improve response rates and remission duration in refractory and relapsed AA. Alefacept is a human recombinant dimeric fusion protein composed of the terminal portion of leukocyte functioning antigen-3 (LFA3/CD58) and the Fc portion of human IgG1. It prevents co-stimulatory signals between antigen presenting cells and memory T cells by competitive inhibition of CD2 in T cells, induces selective apoptosis of CD4+ and CD8+ memory effector T cells by interaction between the Fc portion of IgG1 and the FcyIII in NK cells, and possibly direct ligation of CD2 molecules on T cells that subsequently result in the alteration in T cell agonist signaling. It has been used successfully in the treatment of other T cell mediated disorders particularly psoriasis and steroid refractory graft versus host disease (GVHD) with minimal side effects. In a case of liver transplant associated AA (similar to transfusion associated AA) which is fatal in most patients, Alefacept induced remission after patient did not respond to ATG and other immunosuppressants. The investigators hypothesize that the LFA3-CD2 co-stimulatory pathway play an important role in the immune pathogenesis of AA and treatment with Alefacept can help treat refractory/relapsed cases of AA.