New Sleep Apnea Pill AD109 Cuts Breathing Interruptions by 44% in Phase 3 Trial

A once-nightly pill called AD109 improved obstructive sleep apnea (OSA), a condition in which the airway narrows or collapses during sleep, in a phase 3 trial presented at the 2026 American Thoracic Society (ATS) International Conference. In the SynAIRgy trial, patients taking AD109 had fewer breathing interruptions, less oxygen deprivation and better blood oxygen levels during sleep. More than 40 percent improved enough to move into a less severe OSA category, and 18 percent achieved complete disease control. The findings were published in the American Journal of Respiratory and Critical Care Medicine.

AD109 combines two drugs, aroxybutynin and atomoxetine, to strengthen the throat muscles that keep the airway open, targeting the neuromuscular problems that cause it to collapse during sleep. First author Patrick John Strollo, a sleep medicine physician at the University of Pittsburgh Medical Center, said the results show targeting neuromuscular dysfunction can produce meaningful clinical outcomes.

The six-month trial enrolled 646 adults with mild to severe OSA at 69 sites in the U.S. and Canada, all of whom had refused or could not tolerate CPAP (continuous positive airway pressure), the standard treatment. Among AD109 patients, the apnea-hypoxia index, which measures breathing interruptions per hour, fell by about 44 percent, versus 18 percent with placebo. Other measures, including the oxygen desaturation index and hypoxic burden, also improved, with benefits across different severities and body types.

AD109 showed an acceptable safety profile; side effects were mild and expected. The most common were dry mouth, nausea, insomnia, and difficulty urinating, and about 21 percent of patients stopped treatment because of side effects.

AD109 has received Fast Track designation from the U.S. Food and Drug Administration (FDA) for OSA treatment, and Apnimed has submitted a New Drug Application (NDA) to the agency. Based on FDA feedback, the company expects a potential PDUFA date — the FDA's target decision date — in Q1 2027, if the FDA accepts the NDA for review.