Background and Importance In the elderly patients with AML, both the development of reduced-intensity conditioning (RIC) regimens and the use of haploidentical donors have improved their accessibility to allo-HCT.

Aim and Objectives To analyse the clinical characteristics and results of haploidentical family donor allo-HCT, performed in our hospital during the years 2014 to 2021, in patients with AML >55 years.

Retrospective observational study. Data collected: age, sex, HCT status, time from diagnosis to transplant, ECOG Performance Status, comorbidity indexes (HCT-CI, EBMTs, DRindex), haematopoietic progenitor source (HPS), CMV-mismatch, conditioning regimen, graft-versus-host disease (GVHD) prophylaxis, and post-HCT complications. Overall survival (OS) and progression free survival (PFS) were analysed using Kaplan-Meier.

Results Thirty patients were included. Median (range): 64(56–71) years, 57% women. 70.3% in first complete remission. Median (range) time from diagnosis was 6.5 (3.47-52.37) months.74% ECOG 0. 33% DR index high and very high 15% patients. The EBMTs >4 in 26% and the HCT-CI ≥3 in 56% patients. HPS was peripheral blood in 52% and bone marrow in 48%. 56% CMV-mismatch (donor -/patient +). All patients received a RIC regimen and post-HCT cyclophosphamide and 89% tacrolimus as the only immunosuppressant.

Major non-haematological toxicities included mucositis, gastrointestinal and liver toxicity in 26%, 19% and 7% of patients, respectively. 19% patients developed haemorrhagic cystitis, one patient underwent thrombotic microangiopathy, 41% developed acute GVHD and 37% patients presented chronic GVHD cmv infection occurred in 78% of patients.

Median (range) follow-up was 21.55 (1.67-89.80) months, OS at 1 year was 65% (95% CI, 46-83%), at 2 years 56% (95% CI, 36-75%). PFS at 1 year was 61% (95% CI, 42-80%), at 2 years 48% (95% CI, 28-68%). 48% are still alive and all in complete remission.

Conclusion and Relevance The small sample prevents numerous affirmations from being emphatically extracted, but the results obtained, which are very comparable to the published experiences, support the use of this type of donor in this patient population. Currently, we should not delay transplantation in elderly patients with AML trying to find an HLA-identical donor. If the experience of the Centre is extensive, performing a transplant from a haploidentical donor should be considered in the algorithm of the Allo-HSCT procedure.

Conflict of Interest No conflict of interest