Male or female, 18 to 65 years of age

Willing and able to give informed consent and comply with study requirements

Documented physician-diagnosed asthma for ≥ 4 months prior to Screening

Body mass index (BMI) ≥ 18.0 and ≤ 35.0 kg/m2 at Screening and weighs ≥ 50 kg at Screening.

Women of child bearing potential must have a negative pregnancy test

Males and females must use a highly efficient birth control method

Pre-bronchodilator FEV1 ≥ 70% predicted

Documented allergy to at least one common allergen

Dual responder to inhaled bronchial challenges

Effect of Inhaled TD-8236 on Allergen-induced Asthmatic Response