Outcome following Reduced-Intensity Allogeneic Stem Cell Transplantation (RIC AlloSCT) for relapsed and refractory mantle cell lymphoma (MCL): a study of the British Society for Blood and Marrow Transplantation.

Reduced-intensity allogeneic stem cell transplantation (RIC-AlloSCT) is being increasingly considered for patients with aggressive lymphoma, but limited evidence exists in mantle cell lymphoma (MCL). We report a retrospective study of transplant outcomes of RIC-AlloSCT for MCL in 70 patients (median age, 48 years, range: 30-67 years), with 57 patients receiving an Alemtuzumab-containing regimen. Thirty-four percent of patients had received a prior autologous stem cell transplant. The 1- and 5-year nonrelapse mortality (NRM) was 18% (95% confidence interval [CI] 10-27) and 21% (95% CI 12-31), respectively. The incidence of severe (grade III and IV) acute graft-versus-host disease (aGVHD) was 10%, and the 5-year incidence of chronic GVHD (cGVHD) was 61%. The cumulative relapse risk was 65% (95% CI 48-77) at 5 years, significantly affected by disease status at transplant (P = .0495), specifically the presence of chemosensitive disease (P = .0364). Fifteen of 18 relapsed patients received donor lymphocyte infustion (DLI) (n = 14) or a second RIC-AlloSCT (n = 1), with 11 of 15 currently in CR. The 5-year overall survival (OS) and progression-free survival (PFS) were 37% (95% CI 25%-56%) and 14% (95% CI 6%-34%), respectively. Age at transplantation and having <2 prior lines of therapy influenced the OS, whereas having <2 prior lines of therapy was the only factor to influence PFS. The use of Alemtuzumab in the conditioning was associated with an improved OS at 3 years (P = .0271). RIC-AlloSCT is a potential treatment modality for aggressive MCL. For patients relapsing post-AlloSCT, the disease is salvageable with DLI. The timing of RIC-AlloSCT should be explored in prospective studies to establish the optimal role in the management of this aggressive lymphoma.