The medicine promises to be an alternative to CPAP devices, which are rarely used because they are uncomfortable.
A new experimental pill for obstructive sleep apnea could offer millions of patients a long-awaited alternative to cumbersome CPAP machines, following promising results from a major phase 3 clinical trial in North America.
Researchers say the nighttime medication, known as AD109, significantly reduced respiratory interruptions during sleep in patients with mild to severe obstructive sleep apnea — a disorder that affects about billion people around the world.
Obstructive sleep apnea occurs when the upper airway repeatedly collapses during sleep, briefly stopping breathing and causing patients to breathe hard all night. The condition is associated with daytime fatigue, headaches, difficulty concentrating, cardiovascular disease and long-term cognitive problems.
The standard treatment for sleep apnea has long been the CPAP device (continuous positive airway pressure), which keeps the airway open by delivering pressurized air through a mask worn during sleep. Although highly effective, many patients have difficulty using the devices due to discomfort, noise or inconvenience, which leads to poor treatment adherence.
The new study, published in the American Journal of Respiratory and Critical Care Medicine, tested whether a pharmaceutical approach could offer a simpler solution.
The researchers recruited 646 adults from the United States and Canada who had refused or could not tolerate CPAP therapy. Participants were randomly assigned to receive AD109 or a placebo over a 26-week period, without knowing which treatment they had received.
The study measured success using the apnea-hypopnea index (IAH), the standard method for assessing the severity of sleep apnea based on the number of breathing interruptions experienced each night, explains the .
At the end of the study, patients who took AD109 showed a reduction of approximately 44% in their AHI scores, compared to an 18% reduction in the placebo group. Almost 42% of patients who took the drug showed enough improvements to move to a lower severity category, while almost 18% no longer met the criteria for obstructive sleep apnea.
Treatment was generally well tolerated, with participants reporting mostly mild side effectssuch as dry mouth, nausea and insomnia. AD109 combines two existing medications: aroxibutynin, which acts on the nervous system, and atomoxetine, commonly prescribed for ADHD. Together, the medications help maintain upper airway muscle tone during sleep, preventing airway collapse.
The US Food and Drug Administration (FDA) has granted the treatment accelerated review status, with a regulatory decision for 2027.
