A once-nightly oral pill helped control obstructive sleep apnoea in a large, phase 3 clinical trial presented at the 2026 ATS International Conference. The drug, called AD109, is the first therapy to treat OSA by addressing its underlying mechanisms and targeting the neuromuscular causes of airway collapse. The trial results will be published in the American Journal of Respiratory and Critical Care Medicine.
The trial, called SynAIRgy, showed that patients who took AD109 had fewer breathing interruptions during sleep, less oxygen deprivation, and improved blood oxygen levels overall. More than 40 percent of patients saw their OSA disease severity category improve, and 18 percent achieved complete disease control.
“These results provide encouraging evidence that targeting neuromuscular dysfunction can translate into meaningful clinical outcomes, aligning with our evolving understanding of the disease biology,” said first author Patrick John Strollo, MD, a sleep medicine physician at the University of Pittsburgh Medical Center.
Continuous Positive Airway Pressure (CPAP) is the gold standard treatment for OSA, but many patients are unable to tolerate treatment. AD109 could help fill that gap with an easier treatment option, Dr Strollo said.
“In many other chronic diseases, such as cardiovascular disease, asthma, or type 2 diabetes, it would be unthinkable for the majority of diagnosed patients to remain untreated or undertreated. Yet that remains the reality in OSA,” he said. “An oral pill that targets the underlying neuromuscular drivers of airway collapse during sleep could help address this gap and broaden the range of effective options for patients who remain untreated today.”
AD109 combines two medications, aroxybutynin and atomoxetine, which work together to support muscles in the throat and prevent the airway from sagging or collapsing during sleep.
For the trial, which ran for six months at 69 sites across the U.S. and Canada, researchers enrolled 646 adults with mild to severe OSA who couldn’t tolerate or refused CPAP.
Patients taking AD109 saw their apnea-hypoxia index, which measures the number of breathing interruptions per hour, decrease by about 44 percent, compared with 18 percent in the placebo group. Oxygen desaturation index (the number of times during the night that blood oxygen drops) and hypoxic burden (oxygen deficiency) also improved in the AD109 group.
Importantly, improvements were observed consistently across a broad range of patients, including those with varying severity levels and body types.
Along with improved outcomes, the drug showed an acceptable safety profile with mild, expected side effects. The most common side effects were dry mouth, nausea, insomnia, and difficulty urinating. Around 21 percent of patients discontinued therapy due to side effects.
Dr Strollo noted that the results will be published alongside a companion mechanistic review by ATS in the American Journal of Respiratory Cell and Molecular Biology.
“Together, these peer-reviewed articles connect late-stage clinical outcomes with the biological mechanisms that drive the disease, targeted by the mechanism of action of AD109, providing a more complete and integrated view of OSA and strengthening confidence in the approach,” he said.
AD109 has received Fast Track designation from the FDA for the treatment of OSA, recognising the significant unmet need for effective, well-tolerated pharmacologic therapies for OSA. Apnimed has submitted its New Drug Application (NDA) for AD109 to the FDA. Based on FDA feedback, Apnimed expects a potential PDUFA target action date in 1Q 2027, subject to FDA acceptance of the NDA for review.
Source: American Thoracic Society
