Preparing Patients for Reduced-Intensity Allogeneic Transplants
Because many patients are unable to withstand myeloablation, clinical researchers are studying the feasibility of reduced-intensity nonmyeloablative regimens. Before infusing donated blood-forming stem cells, the patient receives low-dose or standard-dose chemotherapy and/or radiation therapy. Afterward, the patient is given immunosuppressant steroid drugs to help prevent the body from rejecting the transplant. Sometimes the patient also receives an infusion of donated immune cells (white blood cells from the same donor who supplied stem cells) to enhance the graft's attack on the patient's cancer (graft vs. tumor benefit).
This approach is new, so clinical researchers do not have extensive data on its effectiveness. Graft versus host disease sometimes occurs. So far, rates of graft vs. host disease using this approach are similar to those after high-dose conditioning regimens, but the onset is often delayed by weeks and months. Insurance companies and Medicare administrators, who view reduced-intensity transplants as experimental, often do not cover them.