Allogeneic stem cell transplantation for mantle cell lymphoma--final report from the prospective trials of the East German Study Group Haematology/Oncology (OSHO).

This study was conducted in order to evaluate allogeneic stem cell transplantation (alloSCT) as consolidation for patients with mantle cell lymphoma (MCL). Patients with MCL were included into two prospective trials OSHO #060 (refractory/relapsed) and #074 (de novo). Induction was rituximab and chemotherapy. Responding patients proceeded to alloSCT. Minimal residual disease was monitored by quantitative RT-PCR detecting either t(11;14) or clonospecific CDR-III regions. In case of circulating lymphoma cells, immunomodulation (cyclosporine A withdrawal, rituximab, donor lymphocyte infusion) was initiated. Thirty-three of 39 patients underwent alloSCT after myeloablative (n = 7) or toxicity-reduced (n = 26) conditioning. Leukocytes engrafted at day +16 (median, range 0-101) and platelets at day +14 (0-142). Acute graft-versus-host disease stages I-II occurred in 42 % and stages III-IV in 15 %. Five patients have relapsed after SCT. The overall mortality after SCT was 24 % (n = 8). Median follow-up after SCT was 2.8 years (range 0.0-10.9). Five-year progression-free survival was 67 %, and overall survival 73 % after SCT. The results were comparable for primary MCL and refractory/relapsed disease as well as for related vs. unrelated SCT. Younger patients had a significantly better outcome than the elderly. AlloSCT is a feasible and promising consolidation therapy for relapsed and refractory disease and an attractive option for young patients with de novo MCL of high risk.