['asthma']
['rpl554', 'salbutamol', 'placebo']

        Inclusion Criteria:

          -  Provided written informed consent

          -  Males agree not to donate sperm and either be abstinent or use adequate contraception.
             Females to be post-menopausal or surgically sterile

          -  Non-smoker or ex-smoker >6 months

          -  Diagnosed asthma for at least 6 months

          -  Pre-bronchodilator FEV1 ≥60% and ≤90% of predicted normal value and ≥1.5 L at
             screening

          -  Increase in FEV1 of 15% within 30 minutes after a 2.5mg dose of nebulised salbutamol

          -  Systolic blood pressure 90 to 145 mmHg, diastolic blood pressure 50 to 90 mmHg and
             heart rate 45 to 80 beats per minute (bpm) after resting for 5 minutes in a supine
             position (average from two measurements)

          -  Capable of withdrawing from LABAs, LAMAs and SAMAs before screening and during study
             and SABAs before screening and for 8 hours before each dose

        Exclusion Criteria:

          -  Asthma exacerbation in the last 3 months

          -  Any prior life threatening episode of asthma (intensive care admission)

          -  Any clinically significant disease or disorder or clinically relevant screening result

          -  QTcF interval >450 ms or QT interval >500 ms or other abnormality in ECG

          -  History of ischemic heart disease or heart failure. History of recurrent or current
             clinically significant arrhythmia or ECG abnormality as judged by the investigator

          -  Treatment with systemic glucocorticosteroids within 30 days before screening

          -  A suspected/manifested infection according to WHO risk classification 2, 3 or 4
      