The evolution of treatment strategies for patients with chronic myeloid leukemia relapsing after allogeneic bone marrow transplant: can tyrosine kinase inhibitors replace donor lymphocyte infusions?

The optimal treatment for chronic myeloid leukemia (CML) relapsing following allogeneic bone marrow transplant (alloBMT) is unknown. We performed a single-center retrospective analysis of 71 consecutive patients undergoing alloBMT for CML from 1995 to 2008. A multi-state model was used to quantify cumulative incidences of complete molecular response (CMR) and death following alloBMT. The primary analysis was comparison of three treatment interventions (tyrosine kinase inhibitor: TKI, donor lymphocyte infusion: DLI, and TKI + DLI) for relapsed disease post-alloBMT. Forty-five (63%) patients relapsed post-alloBMT (molecular relapse: n = 16, cytogenetic relapse: n = 20, hematologic relapse: n = 2, advanced phase relapse: n = 7) and 40 patients underwent one of three treatments: TKI-only (n = 13), DLI-only (n = 11) or TKI + DLI (n = 16). Although not statistically significant, the TKI-only group had the highest cumulative incidence of CMR and lowest cumulative incidence of death compared to DLI and TKI + DLI. These data support the finding that TKI therapy is active in the post-alloBMT setting.