Syngeneic HSCT confers higher relapse rates, lower nonrelapse mortality in AML patients

Though relapse tends to be higher with syngeneic (Syn) haematopoietic stem cell transplantation (HSCT), it confers lower rates of nonrelapse mortality (NRM), making such procedure a viable alternative treatment option for acute myeloid leukaemia (AML) patients in first complete remission, a recent study has found.

Thirteen Syn HSCT AML patients were enrolled and compared against other patients who received SCT transplants autologously (Auto; n=39) or from mismatched donors (MUD; n=39) or mismatched sibling donors (MSD; n=39). The primary outcome was 5-year overall survival (OS) after HSCT; secondary ones included 5-year leukaemia-free survival (LFS), cumulative incidence of relapse, and cumulative incidence of NRM, among others.

Syn HSCT patients had a 5-year OS rate of 68.4 percent, which was only nominally higher than that in the Auto (55.9 percent; p=0.265), MSD (62.4 percent; p=0.419), and MUD (63.7 percent; p=0.409) groups. Similarly, 5-year LFS was not statistically significant across groups.

In contrast, Syn patients saw higher rates of relapse (46.2 percent) as compared with the MSD (16.7 percent; p=0.02) and MUD (22.2 percent; p=0.063) groups; no such difference was reported for the Auto group (46.9 percent; p=0.922).

However, such relapse disadvantage was offset by significantly lower 5-year cumulative incidence rates of NRM in Syn (0.0 percent) as opposed to the MSD (26.7 percent; p=0.025) and MUD (p=0.034) groups. No difference was reported for Auto (14.4 percent; p=0.129).