Comparing Efficacy and Safety of Inhaled SNG001 to Placebo

Inclusion criteria

1. Male or female aged 18 to 65 years of age at the time of screening. 2. Symptoms of asthma for at least 2 years pri or to the Screening Visit, confirmed by a medical history and: 1. ≥12% and 200mL bronchodilator reversibility at screening or documented in the past, OR, 2. evidence of bronchial hyper-responsiveness at screening or documented in the past, OR, 3. a documented hospital admission (including an Accident and Emergency admission) for asthma since the age of 18, OR. 4. documented evidence that they have attended their GP surgery, out-of-hours clinic (or alternative health care provider) for worsening of asthma symptoms, since the age of 18 3. Must answer Yes to the question Does a cold make your asthma worse? 4. To have had at least one asthma exacerbation suspected to have been caused by a respiratory virus in the last 24 months which required the use of oral steroids and/or additional treatment with antibiotics on one or more occasion. 5. Must be taking regular inhaled corticosteroids. 6. Pre-bronchodilator FEV1 ≥ 40 % predicted at screening. 7. Post-bronchodilator FEV1 ≥ 50 % predicted at screening. 8. Provide written informed consent. 9. Females of childbearing potential must be using a medically acceptable adequate form of birth control and agree to maintain this usage throughout the duration of and four weeks post the Treatment Phase of the study. 10. Motivation (in the Investigators opinion) to complete all study visits, the ability to communicate well with the Investigator and be capable of understanding the nature of the research and its treatment including its risks and benefits.