Prevention of graft vs. host disease with alemtuzumab ‘in the bag’ decreases early toxicity of stem cell transplantation and in multiple myeloma is associated with improved long-term outcome

BackgroundAllogeneic stem cell transplantation in multiple myeloma (MM) is controversial because treatment-related mortality and relapse remain a substantial challenge.MethodsPatients with symptomatic MM responsive to therapy received myeloablative conditioning with radiotherapy (n=12) or chemotherapy (n=10) followed by infusion of HLA-identical grafts from a sibling. Graft vs. host disease (GvHD) prophylaxis consisted of ‘ex vivo’ T-cell depletion with CAMPATH-1 antibody. The objective of the study was to determine transplant-related mortality (TRM), GvHD, overall survival (OS) and Disease free Survival (DFS).ResultsTwenty-two patients, median age 45 (range 37–56) years, had a median performance status of 1 (0–2). Patients received a median of 23.8 × 104/kg CFU-GM and 4.31 × 106/kg CD34. Median time to engraftment was 13 days. The day-100 and 1-year TRM was 9% and 20%, respectively. Ten patients suffered disease recurrence. Four of eight patients remained in remission after infusions of donor lymphocyte (DLI) containing a median total of 0.67 × 108/kg CD3 cells. Three-year OS was 56%, and 50% remained disease free at a median of 1101 days (range 385–5309). Multiple regression analysis showed that bone marrow (vs. peripheral blood stem cell) (P=0.03), presentation of low albumin (P=0.02) and a higher dose of CAMPATH-1H (P=0.01) were adverse factors for survival. Cox analysis confirmed that a lower CAMPATH-1H dose was associated with improved outcome.DiscussionIn chemotherapy-responsive patients with myeloma, T-cell depletion of allogeneic grafts was associated with an acceptable 1-year TRM and seemed to have a favorable impact on long-term survival.