Tandem autologous-allogeneic nonmyeloablative sibling transplantation in relapsed follicular lymphoma leads to impressive progression-free survival with minimal toxicity.

Autologous stem cell transplantation (ASCT) prolongs survival in patients with relapsed follicular lymphoma. ASCT is usually not curative, however. Myeloablative allogeneic transplantation has produced long-term survival at a cost of significant transplantation-related mortality (TRM), whereas reduced-intensity transplantation entails less TRM but has a higher relapse rate. We thus initiated a protocol consisting of ASCT followed by nonmyeloablative allogeneic transplantation (NMT) for relapsed follicular lymphoma to mimic myeloablative allogeneic transplantation without the associated toxicity. The NMT was non-T cell-depleted, and all donors were HLA-identical siblings. We report results in 27 patients with a median age of 49 years (range, 34-65 years). Five patients demonstrated histological progression toward an aggressive lymphoma. The patients had received a median of 3 lines of previous therapy. Disease status before ASCT included 8 patients in complete remission, 14 in partial remission, and 5 refractory. Five patients developed grade II-IV acute graft-versus-host disease, and 20 patients developed chronic graft-versus-host disease requiring systemic therapy. With a median follow-up of 39 months after NMT, overall survival and progression-free survival were 96% at 3 years. We conclude that the combined ASCT-NMT strategy appears to be safe, with excellent progression-free survival even in refractory and transformed cases. This novel approach warrants further investigation in larger prospective studies.