Autologous bone marrow transplantation with negative immunomagnetic purging for aggressive B-cell non-Hodgkin's lymphoma in first complete remission.

To evaluate the effect on survival of negative immunomagnetic purging in aggressive B-cell non-Hodgkin's lymphoma (NHL), 20 patients retrospectively staged according to the age-adjusted International Prognostic Index as high-intermediate (11 patients) or high-risk (9 patients) received autologous bone marrow transplantation (ABMT) in first complete remission (CR1). All patients received six to eight cycles of a F-MACHOP-like protocol as induction treatment and then underwent high-dose chemotherapy (HDC) with a CBV-like regimen. Negative purging included a panel of monoclonal antibodies against B-cell antigens and immunomagnetic beads. The data were compared to a historical control of 18 patients with the same characteristics treated in our institution who received unpurged bone marrow support. The median yield of mononuclear cells (MNC), colony-forming units-granulocyte/macrophage (CFU-GM), and CD34+ cells after purging were 52%, 49%, and 57%, respectively. The median B-cell depletion after negative selection was 1.8 logs. All patients obtained a complete engraftment with no significant differences between the purged and unpurged group. Two toxic deaths (one for each group) were observed and the main extrahematological toxicities were mucositis, vomiting, and diarrhea. The event-free survival (EFS) and overall survival (OS) at 3 years for the whole group of 38 patients were 73% (95% CI: 59-88%) and 81% (95% CI, 68-94%), respectively. The comparison between patients receiving purged marrow and patients receiving unmanipulated marrow indicated no significant survival differences between the two groups both for EFS 84% (95% CI: 67-100%) vs 61% (95%CI: 39-84%) ( P=0.12) and OS 84% (95% CI: 69-100%) vs 71% (95% CI: 50-93%) ( P=0.58). Our report shows that HDC followed by reinfusion of autologous bone marrow can produce long EFS and OS in high-intermediate and high-risk patients with B-cell NHL transplanted in CR1, but was not be able to demonstrate a significant clinical advantage using immunomagnetic purged marrow. However, the use of ex vivo negative purging combined with innovative treatment modalities (peripheral blood stem cell transplant, in vivo administration of monoclonal antibodies) needs to be explored.