Safety And Efficacy of Sub-Myeloablative Allogeneic Stem Cell Transplantation For Patients With Myeloproliferative Disorder (MPD), Myelodysplastic Syndrome (MDS), Acute Myelogenous Leukemia (AML) or Chronic Myelogenous Leukemia

Patients are being asked to participate in this study because they have a malignant blood disease such as Myelodysplastic Syndrome (MDS), Myeloproliferative Disorder (MPD), Acute Myelogenous Leukemia (AML) or Chronic Myelogenous Leukemia (CML). We feel that patients could benefit from an allogeneic (meaning the cells come from a donor other than themself) stem cell transplant. The donor would be a family member or an unrelated person that is felt to be a good match for the patient. Stem cells are cells that are made in the bone marrow (spongy material that fills the middle of the bones). As the stem cells grow, they change into different types of blood cells that they need. This includes red blood cells that carry oxygen around the body, white blood cells that help to fight infections, and platelets that help to prevent and stop bleeding. Usually, patients are given high doses of chemotherapy before a stem cell transplant. High doses of chemo destroy the bone marrow. Healthy stem cells from a donor are then given to replace the patient's unhealthy cells. However, because of complications with the patient's disease, they have a high risk of having life-threatening side effects. These include serious damage to organs such as the lung, liver, kidney and heart. There is also an increased risk of bacterial, fungal, and viral infections. The other major problem is when a donor's stem cells (also called the graft) find that the patient's cells ( the host cells) are not the same. The donor cells may try to destroy the host's cells. The cells at high risk are those of the skin, liver and intestines. This is called graft versus host disease (GVHD) and it can be fatal.

Recently, doctors have been able to use less toxic chemotherapy treatments before patients receive their transplants. This less toxic treatment helps reduce some of the treatment related problems mentioned above. Patient's are being asked to be involved in a research study that uses this approach. One major risk of this low dose treatment is that the patient's body may reject the donor cells. This is called graft rejection. This study is designed to see if this low dose treatment is safe and effective.

This treatment plan adds CAMPATH 1H (a special protein called an antibody) to a low dose chemotherapy regimen. After chemo, the patient will receive an allogeneic (cells come from a donor) stem cell transplant. Adding CAMPATH 1H to the transplant medicines may help in treating the disease. CAMPATH 1H may reduce life-threatening and treatment related side effects like GVHD. CAMPATH 1H stays active in the body for a long time which means it may work longer to prevent GVHD. CAMPATH 1H destroys lymphocytes, a type of white cells that help fight infection, and this helps prevent graft rejection.

We want to see if the addition of CAMPATH 1H to the patient's pre-transplant low dose chemotherapy will decrease the side effects from an allogeneic stem cell transplant, while providing a curative treatment for patients with blood disorders.