This is a randomized, 4-period, placebo-controlled, crossover, phase 2 clinical study to examine the efficacy and safety of AD109 versus its individual components or placebo in patients with obstructive sleep apnea.

The study is designed to examine the efficacy and safety of AD109 to treat obstructive sleep apnea. The study is a four-period single-dose randomized crossover design in which patients will undergo overnight polysomnographic (PSG) testing with dosing of one of the following 4 treatments: AD109, atomoxetine, R-oxybutynin or placebo. Participants will return 2 weeks after their final crossover PSG for an end of study (EOS) visit.

Inclusion Criteria:

• Male or Female, between 25 to 65 years of age, inclusive, at the Screening Visit.
• AHI 10 to <20, or AHI ≥20 if meets other PSG criteria

Exclusion Criteria:

• History of narcolepsy.
• Clinically significant craniofacial malformation.
• Clinically significant cardiac disease (e.g., rhythm disturbances, coronary artery disease or cardiac failure) or hypertension requiring more than 2 medications for control. A medication for these purposes is defined by dosage form, such that a combination antihypertensive medication is considered 1 medication
• CPAP should not be used for at least 2 weeks prior to first study PSG
• History of using oral or nasal devices for the treatment of OSA may enroll as long as the devices are not used during participation in the study.

Adverse Events were monitored for 14 weeks (Screening period, up to 4 weeks; 3-period crossover, up to 8 weeks; End of Study Evaluation, 2 weeks post crossover period).

The study analysis did not analyze data by period. AEs were reported for the safety analysis by number and percent for treatment group only.