A Cambridge biotech may have found a way to put some sleep apnea masks back in the closet. Local firm Apnimed says its experimental pill, AD109, sharply cut the number of nightly breathing interruptions in two large phase 3 trials, positioning the once-at-bedtime drug as a potential alternative for people who refuse or cannot tolerate CPAP machines.
Large reductions in breathing interruptions
In the 646-participant SynAIRgy study, patients who took AD109 once a night saw a mean 55.6% drop in their apnea-hypopnea index (AHI) from baseline at 26 weeks compared with placebo, according to Apnimed. A second phase 3 study, LunAIRo, also hit its primary endpoint, reporting a 46.8% mean AHI reduction at 26 weeks and significant improvements in hypoxic burden, per Apnimed. In its announcements, the company said neither trial identified serious treatment-related adverse events in the phase 3 program.
Side effects and tolerability
The safety backdrop is not all rosy. Earlier trials documented tolerability issues, including some that were annoying enough to prompt people to bow out early. A randomized phase 2 study found dry mouth, urinary hesitancy and insomnia among the most common side effects, with roughly one quarter of participants in some treatment arms reporting dry mouth or insomnia. Those symptoms led to several early discontinuations in shorter studies, according to the randomized MARIPOSA trial in the American Journal of Respiratory and Critical Care Medicine. Regional coverage and outside researchers have urged regulators and clinicians to scrutinize the full safety tables and longer-term cardiovascular outcomes before anyone declares victory.
How AD109 works
AD109 is a combination pill that pairs atomoxetine, a norepinephrine-reuptake inhibitor at a 75 mg dose, with aroxybutynin, a 2.5 mg novel antimuscarinic. Together, they are designed to ramp up signaling to the hypoglossal motor nucleus and increase tone in the upper-airway dilator muscles during sleep. The idea is to keep the airway from collapsing in the first place instead of forcing air through with a mask. That neuromuscular strategy and how it shaped the phase 3 studies are laid out in a trial-design paper in Contemporary Clinical Trials Communications.
Who might benefit and how big is the need
Apnimed and several outlets have homed in on the same selling point: an oral drug might finally reach the sizable group of people who walk away from CPAP. Some reporting has repeated the company’s estimate that tens of millions of U.S. adults could be candidates for an oral therapy, according to Futura-Sciences. Longstanding adherence research shows CPAP failure or dropout rates in the ballpark of 25% to 50%, and many patients abandon the device early, which helps explain why a pill that works even “just” half as well as ideal CPAP use is attracting this much commercial and clinical attention. BMC Pulmonary Medicine reviews how real-world CPAP persistence and dropout numbers swing widely from study to study.
What happens next
Apnimed is not shy about where it wants this to go. Industry coverage reports that the company has been preparing regulatory filings and was on track to pursue a New Drug Application with the U.S. Food and Drug Administration after the two positive phase 3 trials, with full datasets slated for presentation at medical meetings before any formal review, according to Drugs.com. If a submission is filed and accepted, the FDA’s review and any advisory-committee discussions will determine whether this prescription pill joins, or in some cases potentially replaces, device-based approaches in sleep clinics.
For now, sleep specialists are clear on one point: nobody should ditch their prescribed CPAP or other therapy on the strength of early headlines. Regulators and the medical community still need to dig into the full safety and durability data before deciding whether AD109 really earns a permanent spot on the nightstand.
