Do adults aged 70 years or older with acute myeloid leukemia benefit from allogeneic hematopoietic cell transplantation?

Single cord blood transplantation for acute myeloid leukemia patients aged 60 years or older: a retrospective study in Japan

The availability of alternative donor sources could allow elderly patients to receive allogeneic hematopoietic cell transplantation (HCT). We retrospectively evaluated the outcomes of single-unit cord blood transplantation (CBT) in 1577 patients aged ≥60 years with acute myeloid leukemia (AML) in Japan between 2002 and 2017. In total, 990 (63%) patients were not in complete remission (CR) at the time of CBT. A myeloablative conditioning regimen (52%) and calcineurin inhibitor (CI) + mycophenolate mofetil (MMF)-based graft-versus-host disease (GVHD) prophylaxis (45%) were more commonly used. With a median follow-up for survivors of 31 months, the probability of overall survival and the cumulative incidence of leukemia-related mortality at 3 years was 31% and 29%, respectively. The cumulative incidence of non-relapse mortality (NRM) at 100 days and 3 years were 24% and 41%, respectively. The cumulative incidences of grade II-IV and grade III-IV acute GVHD at 100 days and extensive chronic GVHD at 2 years were 44%, 16%, and 14%, respectively. The cumulative incidence of neutrophil engraftment was 80% at 42 days. Results of multivariate analysis indicated that the following factors were significantly associated with higher overall mortality: performance status ≥1, hematopoietic cell transplantation-specific comorbidity index ≥3, adverse cytogenetics, extramedullary disease at diagnosis, and non-CR status at CBT. By contrast, female sex, HLA disparities ≥2, mycophenolate mofetil-based GVHD prophylaxis, and recent CBT were significantly associated with lower overall mortality. In conclusion, single CBT offers a curative option for AML patients aged ≥60 years with careful patient selection.

Bridging Strategies to Allogeneic Transplant for Older AML Patients

Treatment options for older patients with intermediate or high-risk acute myeloid leukemia (AML) remain unsatisfactory. Allogeneic stem cell transplantation, the treatment of choice for the majority of younger AML patients, has been hampered in elderly patients by higher treatment related mortality, comorbidities and lack of a suitable donor. With the higher availability of suitable donors as well as of reduced intensity conditioning regimens, novel low intensity treatments prior to transplantation and optimized supportive care, the number of older AML patients being successfully transplanted is steadily increasing. Against this background, we review current treatment strategies for older AML patients planned for allogeneic stem cell transplantation based on clinical trial data, discussing differences between approaches with advantages and pitfalls of each. We summarize pre-treatment considerations that need to be taken into account in this highly heterogeneous older population. Finally, we offer an outlook on areas of ongoing clinical research, including novel immunotherapeutic approaches that may improve access to curative therapies for a larger number of older AML patients.