Second allogeneic hematopoietic stem cell transplantation as treatment for leukemia relapsing following a first transplant.

We report 27 patients with relapsed acute or chronic leukemia who underwent a second hematopoietic stem cell transplant (HSCT) from a related or unrelated donor. Seventeen patients were diagnosed with acute myelogenous leukemia (AML), six with acute lymphocytic leukemia (ALL) and four with chronic myeloid leukemia (CML). Ages ranged from 22 to 49 years (median 37); 13 patients were female and 14 male. Relapse was diagnosed between 1 and 45 months after the first HSCT. Sixteen patients who relapsed had received an autologous transplant initially and 11 an allogeneic transplant. Ten patients relapsed within 6 months and 17 patients later than 6 months. Chemotherapy was used as reinduction for relapse after HSCT in 16 patients who had received an autologous transplant and in three who had received an allogeneic transplant, since the latter did not respond to reduction of immunosuppression to induce a graft-versus-leukemia (GVL) reaction. Five of these 19 patients (26%) achieved complete remission (CR), seven patients did not respond to chemotherapy and seven achieved a partial remission (PR). The stem cell source for the second HSCT included bone marrow (n = 12) and PBSC (n = 4) from genotypically identical unrelated donors, PBSC (n = 7) and bone marrow (n = 3) from related donors. Currently eight of the 27 patients are alive and disease-free after the second HSCT. One patient is alive and disease-free after two allogeneic transplants (day +1538), eight patients, who relapsed after an autologous transplant followed by an allogeneic transplant (days +248 to +1140), acute myeloid leukaemia (n = 6) and chronic myeloid leukemia (n = 2) are alive and disease-free. The overall disease-free survival is 30% (8/27). The overall disease-free survival of autologous transplant patients subsequently undergoing an allogeneic transplant is 43% (P = 0.049). It is suggested that a second HSCT is possible for patients with leukemia relapse following the first autologous transplant. A second transplant might also be offered to patients relapsing after the first allogeneic HSCT. Bone Marrow Transplantation (2000) 25, 41-45.