Phase IIa Trial in Participants With Asthma to Evaluate Impact of Intranasal ETH47 on Development of Asthma-related Symptoms Following Rhinovirus Challenge

Inclusion Criteria: 1. Capable of giving signed informed consent which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol. 2. Participants aged ≥18 and ≤65 years at the time of obtaining informed consent. 3. Diagnosis of clinical asthma (\>12% reversibility following short acting beta 2 agonist (SABA) treatment or PC20 methacholine challenge of \<8 mg/mL). 4. Stable (no change in medication or dose) asthma maintenance therapy with inhaled glucocorticosteroids (ICS) or ICS + long acting beta 2 agonist (LABA) for at least 3 months prior to dosing. 5. Clinically stable with no exacerbations within 3 months prior to dosing. 6. Sero-negative test result to RV-A16. 7. Participants must agree to use contraception methods (if applicable). Exclusion Criteria: 1. Any cold symptom within the last month such as sore throat, sneezing, rhinorrhoea, malaise, nasal obstruction or cough. 2. Evidence of current allergic rhinitis, including perennial allergic rhinitis, or rhinosinusitis or nasal polyps. 3. History of or current diagnosis of chronic obstructive pulmonary disease, emphysema, cystic fibrosis or bronchiectasis. 4. The evidence of any other historic, active or chronic disease following a detailed medical and surgical history which, in the Investigator's judgement, puts the participant at risk due to participation in the trial, may influence the results of the trial, or the participant's ability to participate in the trial. This includes a history of emergency room visits or hospital admissions due to common cold. 5. Current vaper or smoker, or ex-smoker who stopped within the last 12 months or with a \>5 year pack history; current vapers may be included if willing to stop prior to Baseline.