Successful treatment with nilotinib for molecular relapse of chronic myeloid leukemia after allogeneic hematopoietic stem cell transplantation in the accelerated phase

Although allogeneic hematopoietic stem cell transplantation (allo-HSCT) is recommended for patients with chronic myeloid leukemia (CML) in the advanced phase, but the prognosis of patients who relapsed after allo-HSCT has been poor. An 18-year-old male CML patient achieved complete molecular response (CMR) with nilotinib following molecular relapse soon after allo-HSCT from an HLA-matched sibling donor in the accelerated phase. There was no acute graft-versus-host disease and minimal residual disease levels gradually increased after allo-HSCT. Nilotinib was prescribed at 800 mg/day and started again when molecular relapse was observed at 6 months after HSCT. He maintains complete donor-type chimerism of myeloid cells and CMR after 18 months of nilotinib treatment and 2 years after allo-HSCT without any donor lymphocyte infusion. Although he experienced a sudden onset of intramuscular hemorrhage, probably associated with nilotinib administration combined with an anti-fungal agent, before allo-HSCT, no adverse events were observed in association with nilotinib treatment for molecular relapse after allo-HSCT. In conclusion, nilotinib is an effective and safe agent for molecular relapse after allo-HSCT for CML patients in the advanced phase.