For patients with refractory/relapsed acute myeloid leukemia (AML), total therapy, as compared with standard care therapy, is linked with satisfactory HRQOL in addition to similar transplant-related mortality (TRM), decreased cumulative incidence of relapse (CIR), and better long-term leukemia-free survival (LFS).

Noting that patients with refractory/relapsed AML have a poor prognosis, the investigators sought to examine clinical outcomes and HRQOL after total therapy, which included allogeneic hematopoietic stem cell transplantation (allo-HSCT) and prophylactic donor lymphocyte infusion (DLI) in the early phase after transplantation. This was followed by multiple measurable residual disease (MRD) and graft-versus-host disease (GVHD)-guided DLIs.

Therapeutic Approach for Refractory/Relapsed AML Needs to Be Enhanced

The study authors noted that while allo-HSCT is recognized as a potentially curative strategy for refractory/relapsed AML, providing a 70% to 90% complete remission (CR) rate, LFS remained at 20% to 40%, and CIR at 2 years after transplantation is as high as 40% to 60%. Therefore, for refractory/relapsed AML, the therapeutic approach needs to be improved.

For a study published in Cancer Communications, researchers analyzed a cohort of 105 patients with refractory/relapsed AML who had received non-T-cell-depleted allo-HSCT.

For patients achieving CR at 30 days after transplantation with no evidence of severe infection, relapse, active GVHD, or organ failure, prophylactic DLI was given at 30 days after transplantation for human leukocyte antigen (HLA)-matched related HSCT or at 45 to 60 days after transplantation for unrelated or haploidentical HSCT. Based on MRD results and whether patients developed GVHD after transplantation, multiple DLIs were later administered.

Nearly All Patients Achieved Complete Remission After Transplantation

Among the total cohort, the cumulative rate of grade 2-4 acute GVHD and chronic GVHD was 40.6% (95% CI, 30.6% to 50.6%) and 73.3% (95% CI, 67.4% to 79.2%), respectively. At 30 days after transplantation, nearly all (98.1%) patients (95% CI, 93.3% to 99.5%) achieved CR. A total of 17.1% of patients did not receive prophylactic DLI (group A), while 82.9% of patients received prophylactic DLI (group B).

In group A, at 5 years after transplantation, the CIR, TRM, and LFS were 31.5% (95% CI, 21.9% to 41.1%), 22.1% (95% CI, 11.3% to 32.9%), and 46.4% (95% CI, 36.8% to 56.0%), respectively. In group B, the CIR, TRM, and LFS at 5 years post-transplantation were 27.6% (95% CI, 17.6% to 37.6%), 21.6% (95% CI, 11.2% to 32.0%), and 50.8% (95% CI, 40.0% to 61.6%), respectively. A total of 48 patients survived and more than 90% of long-term survivors had adequate HRQOL at the end of follow-up,

“… Total therapy is associated with decreased CIR, comparable TRM, better long-term LFS, and satisfactory HRQOL for patients with refractory or relapsed AML, comparable with those in standard of care therapy,” the study authors wrote. “In the future, a multicenter randomized control study may be needed to further confirm our results.”