GvHD and GRFS in patients with acute myeloid leukemia undergoing allogeneic HCT with treosulfan- versus reduced-intensity busulfan-based conditioning: a subgroup analysis of a randomized phase 3 trial.

In 30 seconds

This subgroup analysis of a randomized phase III trial compared treosulfan-fludarabine with reduced-intensity busulfan-fludarabine conditioning in 352 patients aged 31–70 years with acute myeloid leukemia undergoing allogeneic hematopoietic cell transplantation. At 24 months, event-free survival was 65% with treosulfan versus 53% with busulfan (P=0.01). Treosulfan was also associated with less extensive chronic graft-versus-host disease and better graft-versus-host disease-free, relapse-free survival. The findings favor treosulfan across AML risk categories, with a particularly notable event-free survival difference among patients with a comorbidity index score >2.

Key findings

• At 24 months, event-free survival was 65% with treosulfan versus 53% with busulfan (P=0.01).
• Extensive chronic GvHD incidence at 24 months was 15.1% versus 28.1%, respectively (P=0.01).
• GvHD-free and relapse-free survival was 53% with treosulfan versus 40% with busulfan (P=0.02).
• Among patients with a Hematopoietic Cell Transplantation Comorbidity Index score >2, event-free survival was 62% versus 42% (P=0.02).

Why it matters

Conditioning choice can affect both disease control and post-transplant complications. In this randomized-trial subgroup, treosulfan-fludarabine was associated with better event-free and GvHD-free, relapse-free survival, alongside lower extensive chronic GvHD incidence. These outcomes are relevant when weighing transplant regimens, particularly because the reported event-free survival advantage was also seen in patients with higher comorbidity scores.

What to keep in mind

This is a subgroup analysis of a randomized trial, rather than the trial’s overall population analysis; the abstract does not provide further subgroup-specific methodological details.