PHILADELPHIAT-cell depletion had no clear advantage over immunosuppressive drug therapy in patients receiving a matched, unrelated donor bone marrow transplant, John E. Wagner, MD, reported at the 44th Annual Meeting of the American Society of Hematology (ASH abstract 274).
This large multicenter randomized trial produced several interesting results, but the hoped-for reduction in chronic graft-versus-host disease (GVHD) with T-cell depletion was not among them; nor was there an improvement in 3-year disease-free survival, the primary study endpoint.
T-cell depletion was associated with reduced toxicity and reduced risk and severity of acute GVHD, but also with increases in some adverse cancer outcomes. Overall, the treatment comparison was "a wash," Dr. Wagner said at a press conference at the ASH meeting. The results support the conclusion that "matching is still the most critical aspect" of the success of bone marrow transplantation.
The National Heart, Lung, and Blood Institute (NHLBI)-sponsored trial was conducted in 401 patients receiving a transplant for chronic myeloid leukemia (CML) (n = 182), acute myeloid leukemia (AML) (n = 101), acute lymphocytic leukemia (ALL) (n = 88), or other malignancies.
"Because the incidence of GVHD is particularly high in recipients of unrelated marrow, it was hypothesized that T-cell depletion would result in decreased risk of nonrelapse mortality by decreasing the toxicities of infection and GVHD," a possibility that was supported by previous experimental and clinical research, said Dr. Wagner, professor of pediatrics, University of Minnesota, and associate director of the Fairview-University Blood and Marrow Transplant Program, Minneapolis.
All patients received a cyclophosphamide(Drug information on cyclophosphamide)/total-body irradiation regimen and post-transplant cyclosporine. Patients were randomized to undergo T-cell depletion or to receive methotrexate(Drug information on methotrexate) on days 1, 3, 6, and 11 post-transplant.