Survival of patients with PH+ Chronic myeloid leukemia relapsing after an allogeneic stem cell transplant.

Allogeneic blood or marrow stem cell transplantation (SCT) from an HLA-identical sibling is the treatment of choice for younger patients with chronic myeloid leukemia (CML). Using standard conditioning regimens and graft-versus-host disease (GvHD) prophylaxis, more than 50% of patients are alive and well with no sign of disease more than 10 years from transplant. Transplant-related mortality and relapse remain the major obstacles to success. Relapse occurs in about 20% of patients transplanted in first chronic phase (CP) with unmanipulated marrow cells; the risk increases to more than 50% for patients transplanted at a later stage of the disease or those transplanted in first CP with a T-cell depleted marrow. Not all patients who relapse will die as a consequence of disease recurrence. Immune modulation to achieve a graft-versus-leukemia effect, standard therapy for CML, or second allogeneic SCT have all been used with variable degrees of success. Thus some patients may regain complete remission of the disease following withdrawal of immunosuppression, donor lymphocyte infusions (DLI), treatment with α- interferon (IFN), or a second allogeneic SCT. Features of both the patient and the disease influence the efficacy of these salvage treatments