In November 2002, Theravance entered into a collaboration with GlaxoSmithKline (GSK) to develop and commercialize once-daily Long-Acting Beta2 Agonist (LABA) products for the treatment of chronic obstructive pulmonary disease (COPD) and asthma. Beta2 agonists are medicines that work by relaxing the muscles in the wall of the lung airways, allowing the airways to expand (known as bronchodilation) and leading to improved lung function in COPD and asthma patients. The collaboration has resulted in the selection of vilanterol (VI) as the inhaled LABA to be developed for once-daily administration both as a single product for the treatment of COPD and as part of new combination medicines with an inhaled corticosteroid for the treatment of COPD and asthma, RELOVAIR™ and with a long-acting muscarinic antagonist (LAMA) for the treatment of COPD, LAMA/LABA (GSK573719/VI).