Chronic myeloid leukaemia treated by allogeneic bone marrow transplantation from histocompatible sibling donors – an invariably fatal malignancy rendered highly curable

Twenty-eight patients aged 16-50 years with chronic myeloid leukaemia (CML) underwent allogeneic bone marrow transplantation (BMT) using human leukocyte antigen (HLA)-identical sibling donors. Of the 28 patients, 21 were in chronic phase, five were in accelerated phase and two were in blast phase at the time of BMT. Twenty-three of the patients survived more than 63-2187 days after BMT, 21 in continuous complete remission and two with haematologic relapse of CML. Two patients died of interstitial pneumonitis and one died of relapsed CML, cerebral aspergillosis and cytomegalovirus enterocolitis. The overall probability of survival at six years was 78% +/- 9% (mean +/- standard error) and of disease free survival 66 +/- 11%. For patients transplanted in chronic phase, the survival probability was 90 +/- 6%, while all of the patients undergoing BMT in chronic phase within the first year after diagnosis were alive with a relapse-free survival of 88 +/- 12%. The actuarial probability of occurrence of acute graft-versus-host disease (GVHD) was 57 +/- 9%, while for Grades II and III GVHD it was 28 +/- 9%. Chronic GVHD occurred in 18 of 25 patients at risk. The majority of patients had a Karnofsky performance score at latest follow-up of at least 90% (range 50-100). We conclude that allogeneic BMT is effective, curative therapy for CML and that BMT performed earlier in the natural history of the disease is associated with the best outcome.