The purpose of this study is to assess the the ability of a single dose of LAS40468 administered via Genuair® and a single dose of salmeterol/fluticasone propionate (Seretide®) administered via Accuhaler to produce bronchodilation (opening of the airways) and the safety and tolerability of the treatments

This is a Phase 1, randomised, double-blind, double-dummy, cross-over trial to assess the bronchodilation effect of a single dose of LAS40468 and a single dose of salmeterol/fluticasone propionate (Seretide®) administered to adult patients with stable asthma.

The study will consist of a screening visit and treatment periods of approximately 13 hours separated by washout periods of 7 to 14 days from the time of Investigational Medicinal product (IMP) administration.

Inclusion Criteria:

• Adult males and non-pregnant, non-lactating females aged between 18 and 60 years (both inclusive)
• Patients with a confirmed 6-months' history of asthma at the time of enrolment into the trial
• Patients treated with short-acting beta-agonists or inhaled corticosteroids at a stable dose and regimen (up to the equivalent of 1600 μg/day of beclometasone dipropionate) for at least 4 weeks prior to screening
• Patients whose (pre-salbutamol) forced expiratory volume in 1 second (FEV1) at screening is >60% of the predicted normal value after a washout of at least 6 hours for short-acting beta-agonists and 48 hours for long-acting beta-agonists, if applicable
• Patients with a FEV1 absolute increase of at least 250 mL over baseline value after inhalation of 4 puffs of 100 μg of salbutamol in one of two pulmonary function tests performed within 10-15 min

Exclusion Criteria:

• Patients with clinically significant respiratory or pulmonary diseases other than asthma or history of thoracic surgery
• Patients with a Body Mass Index (BMI) < 18 or > 40kg/m2 (both inclusive)