Study results indicated a possible lack of benefit with allogeneic hematopoietic cell transplantation (HCT) in patients with acute myeloid leukemia (AML) who were older or medically infirm. The study’s findings were reported in the journal Blood.
HCT is a potentially curative therapy for AML, but the majority of patients with AML are above 65 years old, according to the researchers who performed the study. They had an aim of prospectively evaluating impacts of HCT on mortality and several patient-reported outcomes.
The researchers found that HCT was associated with a significant survival benefit. “However, this benefit was diminished among all patients and in most of the various prespecified subgroups once we accounted for confounding AML- and patient-specific variables that impacted mortality and, likely, treatment assignment, because these variables disproportionately favored recipients of HCT,” they wrote in their report.
In this US-based, longitudinal, multicenter, prospective, observational trial (ClinicalTrials.gov Identifier: NCT01929408), patients being treated for AML were evaluated for outcomes that were assessed in the context of patient clinical characteristics. Overall survival (OS) was the primary outcome, with quality of life (QOL), functional status, and frailty as secondary outcomes.
There were 692 evaluable patients in the study, of whom 46% had received HCT. Patients of ≥65 years of age represented 43% of the study population. Augmented HCT-Comorbidity Index (HCT-CI) scores were ≥4 in 56% of patients, and patients who had an age of ≥65 years and/or an augmented HCT-CI score ≥4 characterized 68.2% of the population. Most patients (77%) had newly diagnosed AML. European LeukemiaNet (ELN) cytogenetic risk status was intermediate in 43% of patients and adverse in 36%. Survivors had a median follow-up of 53.6 months (range, 1.1-88.5) after treatment initiation.
Patients who had undergone HCT had an estimated 4-year OS rate after HCT of 54% (95% CI, 48-59). Unadjusted analyses of multiple subgroups showed reduced risks of mortality with HCT, compared with not having HCT.
However, when analyses were adjusted according to variables associated with mortality, across most subgroups a survival benefit from HCT appeared to be reduced. Only patients with ELN adverse risk (P =.01) or who did not reach first complete remission (CR1; P =.02) showed a significant OS benefit with HCT in this analysis.
Evaluated subgroups without a morality benefit in adjusted analyses included all patients (P=.19), patients aged ≥65 years (P =.22), patients with augmented HCT-CI scores ≥4 (P =.34), patients with ELN intermediate risk (P =.26), and patients who reached CR1 (P =.75).
QOL and functional status had been evaluated using multiple instruments. In adjusted analyses of these outcomes over time, the researchers did not find significant differences in results for patients after HCT, compared with those for patients who never had HCT.
“In conclusion, this large observational study provides evidence that the current belief that HCT is preferable to no HCT is subject to a large degree of contradiction, making the assessment of HCT difficult outside a randomized clinical trial,” the researchers wrote in their report.
Disclosures: Some authors have declared affiliations with or received grant support from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.
Sorror ML, Gooley TA, Storer BE, et al. An 8-year pragmatic observation evaluation of the benefits of allogeneic HCT in older and medically infirm patients with AML. Blood. 2023;141(3):295-308. doi:10.1182/blood.2022016916