Evaluate the safety and tolerability of a single dose of S-1226 (8%) in subjects with mild atopic asthma.

Phase IIa, placebo-controlled, randomized, double-blind, crossover single dose study to evaluate the safety, tolerability and efficacy of S-1226 (8%) administered by nebulization in subjects with mild atopic asthma

Inclusion Criteria:

1. Male or female subjects 18-40 years of age.
2. BMI of 18-40 kg/m2
3. Subject is not currently on topical or systemic corticosteroids and has not taken any oral/injectable corticosteroid within 60 days prior to study drug administration and has not used any inhaled/nasal corticosteroid within 30 days prior to study drug administration.
4. Female subjects must not be pregnant or lactating and must be practicing an acceptable method of birth control, or be surgically sterile or postmenopausal.
5. Subjects must have had asthma for at least 3 months.
6. Subject is a non-smoker or has not smoked for > 1year and has < 10 pack-year history.
7. Subject has a methacholine PC20 of less than 16mg/mL.
8. Subject has normal laboratory values (normal values as clinically judged by the Investigator) for clinical chemistry, hematology, and urinalysis.
9. Subject is in general good health based on medical history and clinically acceptable results for the following assessments: physical examination, vital signs, and 12-lead ECG, as assessed by study physicians.
10. Subject is able to communicate effectively with study personnel and is reliable, willing and cooperative in terms of compliance with protocol.

Exclusion Criteria:

Subjects to whom any of the following applies will be excluded from the study:

1. Any clinically significant abnormality or abnormal laboratory test results found during medical screening or positive test for hepatitis B, hepatitis C, or HIV found during medical screening.
2. Subjects who require inhaled β2-agonist medication more frequently than 4 times a week (other than prophylactically prior to exercise) during the 4 week period before screening.
3. Subjects who are currently treated with any asthma medication other than inhaled β2-agonist.
4. Subjects with frequent emergency room visits for asthma, with prior ICU admission or those with prior intubation.
5. Presence or history of neurologic, endocrine, hepatic, gastrointestinal or kidney disease or therapy that would jeopardize the subject's well-being by participating in the study.
6. Cardiovascular disease that, in the opinion of the Investigator, is not stable or could put the subject at increased risk by participating in the study.
7. Any reason which, in the opinion of the Investigator (or delegate), would prevent the subject from participating in the study.
8. Clinically significant electrocardiogram (ECG) abnormalities or vital sign abnormalities (systolic blood pressure lower than 90 or over 140 mmHg, diastolic blood pressure lower than 50 or over 90 mmHg, or heart rate less than 50 or over 100 bpm) at screening.
9. Subject has a history of physician diagnosed panic disorder or other anxiety disorders.
10. Subject is currently receiving treatment, or has received treatment in the previous 14 days, with monoamine oxidase (MAO) inhibitors.
11. Subjects dosed with an investigational drug within 30 days prior to the Screening Visit.
12. Subjects dosed with biologic therapy within the previous 4 months or 5 half-lives from baseline methacholine testing.
13. Subject has current (or within the last six months) evidence of alcohol abuse (regularly drinks more than 4 units of alcohol per day; 1 unit = ½ pint of beer, 1 glass of wine, or 1 ounce of spirit)
14. Positive urine drug screen or urine cotinine test at screening.
15. Breast-feeding subject.
16. Positive pregnancy test at screening.
17. Subject, who in the opinion of the Investigator, is mentally or emotionally unsuitable to participate, or unable/unwilling to comply with the study assessments.