Outcome of acute leukemia relapsing after bone marrow transplantation: utility of second transplants and adoptive immunotherapy

Abstract
We studied 231 acute leukemia patients relapsing after allogeneic (n = 114) or autologous (n = 117) BMT to assess the outcome of further therapy. In general, all patients in good condition were eligible for second transplants except for post-allograft relapses from 1993-1994 onwards who received cytokine- or cell-mediated immunotherapy. The major reason for patients not progressing to second graft was death from progressive disease or toxicity of salvage chemotherapy. Seventeen of 231 patients (7%) were alive at the last follow-up. Six of 14 post-autograft relapses treated with second transplants were alive and well, compared with five of 103 not undergoing second grafts (P < 0.0001). One of 23 post-allograft recipients treated with second allografts was alive with an extramedullary relapse, compared with five of 13 receiving immunotherapy and none of 78 receiving standard-dose or palliative therapy (P < 0.0001). We conclude that only a small proportion of highly selected acute leukemia patients relapsing after a transplant reach the stage of a conventional second transplant. In our experience, second allografts after myeloablative therapy in patients relapsing after one allograft are associated with very poor results, and immunotherapy may be a better approach in such cases. Selected patients relapsing after an autograft may become long-term survivors following a second autograft or an allograft.