 This research study adds CAMPATH 1H to a low-dose chemotherapy regimen, followed by an allogeneic stem cell transplantation. We want to see whether adding CAMPATH 1H to the transplant medications helps in treating the disease. We also want to see whether there are fewer life-threatening side-effects from the treatment. CAMPATH 1H is a drug that is still being studied. CAMPATH 1H stays active in the body for a long time after patients receive it, which means it may work longer at preventing graft-versus-host-disease GvHD symptoms. 