Impact of primary disease on outcome after allogeneic stem cell transplantation for transformed secondary acute leukaemia

Myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN) and chronic myelomonocytic leukaemia (CMML) can progress to secondary acute myeloid leukaemia (sAML). We compared the outcome of 4214 sAML patients who received allogeneic haematopoietic stem cell transplantation (allo-HSCT) from an unrelated (62%) or human leucocyte antigen (HLA)-identical sibling donor (38%) according the underlying disease: MDS (n = 3541), CMML (n = 251) or MPN (n = 422). After a median follow up of 46·5 months, the estimated 3-year progression-free (PFS) and overall survival (OS) for the entire group was 36% (34-37%) and 41% (40-43%), respectively. The cumulative incidence of relapse and non-relapse mortality (NRM) was 37% (35-39%) and 27% (26-29%), respectively. In a multivariable analysis for OS, besides age (P