A once-nightly pill cut breathing interruptions by about 44 percent in a large phase 3 trial, offering new hope for the millions of people with obstructive sleep apnea who cannot tolerate CPAP machines.
The drug, AD109, combines two existing medications — aroxybutynin and atomoxetine — to target the neuromuscular dysfunction that causes the airway to collapse during sleep. Results from the SynAIRgy trial, involving 646 adults with mild to severe OSA at 69 sites across the U.S. and Canada, were published September 1 in the American Journal of Respiratory and Critical Care Medicine and presented at the 2026 ATS International Conference.
Patients taking AD109 saw their apnea-hypopnea index — the standard measure of breathing interruptions per hour — fall by roughly 44 percent, compared with an 18 percent reduction in the placebo group. More than 40 percent of treated patients improved enough to move into a less severe disease category, and 18 percent achieved complete disease control. The benefits were consistent across different severity levels and body types.
"These results provide encouraging evidence that targeting neuromuscular dysfunction can translate into meaningful clinical outcomes," said lead author Patrick John Strollo, MD, a sleep medicine physician at the University of Pittsburgh Medical Center. He noted that while CPAP remains the gold standard, a majority of diagnosed OSA patients remain untreated or undertreated, much as it would be unthinkable in cardiovascular disease or asthma.
AD109's safety profile was described as acceptable, with the most common side effects being dry mouth, nausea, insomnia, and difficulty urinating. About 21 percent of patients discontinued the treatment due to side effects.
Apnimed has already submitted a New Drug Application to the FDA, which granted AD109 Fast Track designation. Based on agency feedback, the company expects a potential PDUFA target action date in the first quarter of 2027.
The trial's results come at a time when the sleep medicine field is actively seeking drug-based alternatives for the estimated one billion people worldwide who live with OSA. Previous efforts have focused on GLP-1 agonists for obesity-related apnea or nasal sprays, but AD109 is notable for targeting the neuromuscular roots of the condition itself — the throat muscles that fail to keep the airway open.
If approved, AD109 would represent the first oral medication specifically designed for OSA treatment, potentially reshaping clinical practice for a condition that affects an estimated 40 million U.S. adults.
