Eight-year experience with allogeneic stem cell transplantation for relapsed follicular lymphoma after nonmyeloablative conditioning with fludarabine, cyclophosphamide, and rituximab.

Nonmyeloablative stem cell transplantation in patients with follicular lymphoma has been designed to exploit the graft-versus-lymphoma immunity. The long-term effectiveness and toxicity of this strategy, however, is unknown. In this prospective study, we analyzed our 8-year experience. Patients received a conditioning regimen of fludarabine (30 mg/m(2) daily for 3 days), cyclophosphamide (750 mg/m(2) daily for 3 days), and rituximab (375 mg/m(2) for 1 day plus 1000 mg/m(2) for 3 days). They were then given an infusion of human leukocyte antigen-matched hematopoietic cells from related (n = 45) or unrelated donors (n = 2). Tacrolimus and methotrexate were used for graft-versus-host disease (GVHD) prophylaxis. Forty-seven patients were included. All patients experienced complete remission, with only 2 relapses. With a median follow-up time of 60 months (range, 19-94), the estimated survival and progression-free survival rates were 85% and 83%, respectively. All 18 patients who were tested and had evidence of JH/bcl-2 fusion transcripts in the bone marrow at study entry experienced continuous molecular remission. The incidence of grade 2-IV acute GVHD was 11%. Only 5 patients were still undergoing immunosuppressive therapy at the time of last follow-up. We believe that the described results are a step forward toward developing a curative strategy for recurrent follicular lymphoma.