Definitions of R/R AML according to the 2022 ELN recommendations
| Refractory disease | Failure to achieve CR, CRh, or CRi after |
| Two courses of intensive induction for intensively treated patients or | |
| A defined landmark (eg, 180 d) after starting nonintensive therapy | |
| Relapsed disease | After prior achievement of CR, CRh, or CRi |
| Increase of blasts to ≥5% | |
| Development of extramedullary disease | |
| Reappearance of blasts in the blood in at least 2 peripheral blood samples at least 1 wk apart | |
| MRD relapse | Conversion from MRD negativity to MRD positivity (independent of method) |
| Increase of MRD copy numbers ≥1 log10 between any 2 positive samples in patients with CR, CRh, or CRi in MRD detectable at low levels by qPCR |
| Refractory disease | Failure to achieve CR, CRh, or CRi after |
| Two courses of intensive induction for intensively treated patients or | |
| A defined landmark (eg, 180 d) after starting nonintensive therapy | |
| Relapsed disease | After prior achievement of CR, CRh, or CRi |
| Increase of blasts to ≥5% | |
| Development of extramedullary disease | |
| Reappearance of blasts in the blood in at least 2 peripheral blood samples at least 1 wk apart | |
| MRD relapse | Conversion from MRD negativity to MRD positivity (independent of method) |
| Increase of MRD copy numbers ≥1 log10 between any 2 positive samples in patients with CR, CRh, or CRi in MRD detectable at low levels by qPCR |