Allogeneic, but not autologous, hematopoietic-cell-transplant improves survival only among younger adults with acute lymphoblastic leukemia in first remission: individual-patient-data meta-analysis

A partir de données portant sur 2 962 patients adultes atteints d'une leucémie aiguë lymphoblastique non Ph+ et inclus dans 13 essais cliniques, cette méta-analyse montre qu'une greffe allogénique de cellules hématopoïétiques, et non une greffe autologue, améliore la survie globale des patients de moins de 35 ans

Résumé en anglais

Haematopoietic cell transplant (HCT) and prolonged chemotherapy are standard post remission strategies for adult acute lymphoblastic leukaemia (ALL) in first complete remission (CR1), but optimal strategy remains controversial. There are no randomised trials of allogeneic HCT. Updated individual patient data were collected and analysed from studies with information on availability of matched sibling donor (used to mimic randomisation) and from randomised trials of autograft versus chemotherapy. Data from 13 studies including 2962 patients, excluding Philadelphia positive, showed survival benefit for matched sibling donor (MSD) for patients aged <35 years (OR = 0.79; 95% CI= 0.70-0.90, p=0.0003) but not for those ≥35yrs (OR = 1.01; 95% CI=0.85-1.19, p=0.9; heterogeneity p=0.03), due to higher absolute risk of non-relapse mortality (NRM) for older patients. No differences were seen by risk group. There was a trend towards inferior survival for autograft versus chemotherapy (OR=1.18; 95% CI=0.99-1.41; p=0.06). No beneficial effect of autografting was seen in comparison to chemotherapy in this analysis. MSD myeloblative HCT improves survival only for younger patients, with an absolute benefit of around 10% at five years. Improved chemotherapy outcomes and reduced NRM associated with allogeneic transplants may change the relative effects of these treatments in the future.