Veliflapon (BAY X 1005; DG-031) effectively inhibits the synthesis of LTB4 in A23187-stimulated leukocytes from rats, mice and humans (IC50s of 0.026, 0.039 and 0.22 μM, respectively) as well as the formation of LTC4 (IC50 of 0.021 μM) in mouse peritoneal macrophages stimulated with opsonized zymosan.