Studying Immune System Reconstitution Following Unrelated Donor Transplantation and Graft-Versus-Host-Disease Prevention
Name of the Trial
Phase I/II Randomized Pilot Study of Targeted Immune-Depleting Chemotherapy, Reduced-Intensity Allogeneic Hematopoietic Stem Cell Transplantation from an HLA-Matched Unrelated Donor, and Graft-Versus-Host Disease Prophylaxis Comprising Tacrolimus, Methotrexate, and Sirolimus Versus Alemtuxumab and Cyclosporine in Patients With High-Risk Advanced Hematologic Malignancies or Other Diseases (NCI-07-C-0195). See the protocol summary.
Dr. Michael Bishop and Dr. Steven Pavletic, NCI Center for Cancer Research
Why This Trial Is Important
Allogeneic hematopoietic stem cell transplantation (allogeneic HSCT) is one of the few potentially curative therapies available to patients with some advanced leukemias, lymphomas, or other blood or bone marrow diseases (collectively known as hematologic malignancies). In allogeneic HSCT, patients first receive high-dose chemotherapy and/or radiation therapy to destroy their hematopoietic stem cells; then, stem cells from a donor, either a relative or an unrelated volunteer, are used to restore bone marrow function.
Many patients undergoing allogeneic HSCT receive prophylactic treatment with immunosuppressive or other drugs to prevent graft-versus-host disease (GVHD), a common and potentially serious complication of allogeneic HSCT. GVHD occurs when transplanted cells (the graft) attack the recipient's (the host's) organs and tissues. The effects of GVHD-prevention therapies on immune system reconstitution following allogeneic HSCT are not well understood.
In this clinical trial, patients with high-risk (refractory or progressive), advanced hematologic malignancies will undergo chemotherapy to induce remission; those achieving remission will then undergo reduced-intensity, immune-depleting chemotherapy followed by allogeneic HSCT from a matched, unrelated donor. After HSCT, the patients will be treated with one of two distinct drug regimens that are currently used to prevent GVHD. The researchers will assess the effectiveness and safety of these treatments and examine how the immune system rebuilds itself in these patients.
"The drugs used to prevent GVHD have a significant effect on how the immune system regenerates after stem cell transplant," said Dr. Bishop. "Our purpose with this trial is to study how two proven GVHD-prevention regimens affect immune reconstitution following transplantation from unrelated donors, and then, based on the knowledge we gain, to design future trials to enhance immune system recovery, further reduce toxicity, and strengthen the antitumor activity of HSCT," Dr. Bishop said.