Reduced Dose of Cyclophosphamide to Prevent Graft versus Host Disease after Stem Cell Transplant

Cyclophosphamide is a chemotherapy (chemo) drug often given after a transplant to prevent GvHD. We are doing this study to see if a lower dose of cyclophosphamide after transplant is safer, but just as effective. Cyclophosphamide can prevent GvHD, but it can also make you sick and more likely to get an infection. This study will look at how well a lower dose of cyclophosphamide works to reduce these side effects, while also preventing GvHD. This study does not include any new or untested drugs. The drugs and procedures in this study are standard for transplant.