Within the abemaciclib group of the Japanese subpopulation, discontinuation of any study drug was most commonly due to AEs of increased ALT (n = 4; 10.5%) or AST (n = 2; 5.3%), with 1 patient (2.6%) each discontinuing due to AEs of neutropenia and diarrhea. The gene discussed is GPT; the disease is Decreased total neutrophil count.