ATLG fights GVHD but reduces PFS, OS
For patients who received busulfan and fludarabine, 2-year moderate-severe chronic GVHD-free survival was 33% in the placebo arm and 49% in the ATLG arm (P=0.047). Two-year OS was 66% and 53%, respectively (P=0.520). And 2-year PFS was 58% and 48%, respectively (P=0.540).
The researchers noted that the choice of conditioning regimen had a “profound effect” on ALC at day -3 (the time of ATLG/placebo initiation). More than 70% of patients who received TBI had an ALC <0.1 x 109/L, compared to less than 35% of patients who received busulfan-based conditioning.
ALC, in turn, had an impact on PFS and OS. In patients with an ALC ≥ 0.1 x 109/L on day -3, ATLG did not compromise PFS or OS, but PFS and OS were negatively affected in patients with an ALC < 0.1.
ATLG recipients with an ALC < 0.1 had significantly worse OS (HR=4.13, P<0.001) and PFS (HR=3.19, P<0.001) than patients with an ALC ≥ 0.1. 
