Information Vilanterol trifenatate (GW642444M) is a novel inhaled long-actingbeta2 adrenoceptoragonist with inherent 24-hour activity for once daily treatment of COPD and asthma. Targets β2-adrenoceptor In vitro Vilanterol displays a subnanomolar affinity for the β2-AR that is comparable with that of salmeterol but higher than olodaterol, formoterol, and indacaterol. In cAMP functional activity studies, vilanterol demonstrates similar selectivity as salmeterol for β2- over β1-AR and β3-AR, but a significantly improved selectivity profile than formoterol and indacaterol. Vilanterol also shows a level of intrinsic efficacy that is comparable to indacaterol but significantly greater than that of salmeterol. In cellular cAMP production and tissue-based studies measuring persistence and reassertion, vilanterol has a persistence of action comparable with indacaterol and longer than formoterol. In addition, vilanterol demonstrates reassertion activity in both cell and tissue systems that is comparable with salmeterol and indacaterol but longer than formoterol. In human airways, vilanterol is shown to have a faster onset and longer duration of action than salmeterol, exhibiting a significant level of bronchodilation 22 h after treatment.