The present study compares WAY-126299A to WY-50295T (a simultaneous 5-lipoxygenase [5-LO] inhibitor and leukotriene D4 receptor antagonist) and zileuton (a reference 5-LO inhibitor).Results showed that WAY-126299A retained the dual mechanism of action and the oral potency and efficacy of WY-50295T in an animal model of asthma.In contrast to WY-50295T, WAY-126299A was active as a 5-LO inhibitor in human whole blood.