Addition of Etanercept and Extracorporeal Photopheresis (ECP) to Standard Graft-Versus-Host Disease (GVHD) Prophylaxis in Stem Cell Transplant

This research study investigates the benefits and possible risks of adding both etanercept (Enbrel) and ECP (extracorporeal photopheresis) to the conventional preventative (or prophylactic) treatments for graft-versus-host disease (GVHD). GVHD is a common, serious, and too often fatal, complication after matched unrelated donor stem cell transplantation, regardless of the pre-transplant conditioning regimen used (full or reduced intensity). Reduced intensity transplants which employ lower doses of chemotherapy during the conditioning phase of the transplant, are less toxic than full intensity transplants. Reduced intensity transplants may extend the unrelated donor transplant option to older patients or to patients with existing medical conditions or illness, where a full intensity transplant is not possible. To be successful, reduced intensity transplants need to offset any lower effectiveness in killing cancer cells during the conditioning phase, with the establishment of a donor cell, graft-versus-leukemia effect (GVL). The GVL effect and GVHD are associated with each other and therefore, the goal of GVHD prophylaxis for this study is not so much to prevent all GVHD, but rather to prevent serious and fatal acute GVHD. Most GVHD-related deaths are either the direct consequence of severe GVHD or from infections associated with intense immunosuppression, a consequence of the standard treatments for acute GVHD, which almost always include high-dose steroids. A more effective prophylaxis therapy that allows for the GVL effect to develop, while limiting the exposure to high-dose steroids may reduce transplant mortality and morbidity. We also will study how key chemical and cellular factors relate to clinical outcome.