Study to Assess the Safety and Efficacy of SelK2 on Airway Responses Following Allergen Challenge in Subjects With Asthma (Part 1) and in Subjects With Chronic Obstructive Pulmonary Disease (Part 2)

Part 1: Key Inclusion Criteria * Males or females, 18-65 years of age (inclusive) * Body Mass Index (BMI) ≥ 18.0 and ≤ 35.0 kg/m2 * Documented physician-diagnosed asthma for ≥ 4 months prior to screening * Pre-bronchodilator FEV1 ≥ 70% predicted at screening * Documented allergy to at least one common allergen as confirmed by the skin prick test * Dual responder to inhaled bronchial allergen challenges as manifested by positive allergen-induced early (EAR) and late airway bronchoconstriction (LAR) at screening Key Exclusion Criteria * Lung disease other than stable, mild asthma; e.g., worsening of asthma that requires a change in asthma therapy in the past 4 weeks or is deemed clinically significant by the investigator. * A diagnosed current or recent (within previous 8 weeks of screening, or prior to randomisation) bacterial, protozoal, viral or parasitic infection; is suspected of or is at high risk of having a parasitic infection, or has a history of more than one episode of herpes zoster infection. * Has a history of life-threatening asthma, defined as an asthma episode that required intubation and/or was associated with hypercapnea, respiratory arrest and/or hypoxic seizures. * Has been hospitalised or has attended the emergency room for asthma in the 12 months prior to screening, or prior to randomisation. * A history of tuberculosis (latent or active) or systemic fungal diseases. Part 2: Key Inclusion Criteria * Male or female, 40 to 75 years of age, inclusive, …