ASH: For Unrelated Donor Transplant, Bone Marrow Preferred

The first plenary session at this year’s American Society of Hematology (ASH) was kicked off by the presentation of a study that compared the use of peripheral blood to bone marrow for stem cell transplants from unrelated donors. Although peripheral blood stem cells from related donors had previously shown a clinical benefit, the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Protocol 0201 trial shows that when stem cells come from donors unrelated to the patient, there is no significant difference in patient survival between the use of peripheral blood stem cells or bone marrow stem cells.

Surgeon performs a bone marrow harvest operation

The prospective, randomized trial showed no difference in overall survival 2 years post transplant. Overall survival was 51% for patients receiving peripheral blood stem cells and 46% for those receiving bone marrow stem cells (P = .288).

There were also no differences witnessed between rates of relapse, non-relapse mortality, and acute graft-vs-host disease (GVHD) between patients in the 2 study arms. Engraftment was faster in patients receiving peripheral blood stem cells, however, peripheral blood stem cell transplants were associated with higher rates of extensive chronic GVHD (48% vs 32%).

Transplant centers are increasingly using peripheral blood stem cells as a source of adult stem cells mainly because data from clinical trials showed their superiority when donors are related to the patient, but a comparison with unrelated donors had not been done until this trial. The trial included over 270 patients in each arm from centers in the United States and Canada.

Because of the higher chronic GVHD observed in patients receiving peripheral blood stem cells, the presenter of the study, Dr. Claudio Anasetti, MD, of the H. Lee Moffitt Cancer Center & Research Institute in Tampa, Florida, raised the question of whether the increased use of peripheral blood stem cells is justified.

Based on these study results, Dr. Anasetti believes that both stem cell sources are acceptable because of the similar survival outcomes, but that bone marrow stem cells may be preferred for patients at risk for graft failure or early serious infections. The study did show that peripheral blood performed better than bone marrow in respect to fewer graft failures (2.7% vs 9.1%). However, for the majority of patients, the speaker stated that bone marrow stem cells could be used.

When asked about the cost-effectiveness of both techniques, Dr. Anasetti noted that although the initial hospital stay is shorter when using bone marrow for transplant, the total days in the hospital in the first year after transplant was not different between the 2 arms.