APG101 significantly decreased GVHD-induced death in a minor histocompatibility-mismatched BMT model. (A-C) Lethally irradiated BALB/c recipient mice were reconstituted with TCD BM from B10.D2 mice with or without B10.D2-derived spleen cells (SCs) and were treated with PBS or APG101 starting 1 day before transplantation (day −1). Survival (A) and GVHD-scores (B) were determined and surviving animals/total animals treated are indicated in panel A. TCD BM+SC (PBS) versus TCD BM+SC (APG101; ***P < .001). Histologic signs of GVHD in liver, skin, and intestine of 6 to 10 animals/ treatment group were either determined the day mice were killed because of their moribund state and for all surviving mice at the end of the experiment. Data are from 1 experiment performed.