Apnimed has scored another phase 3 knockout. The Massachusetts biotech’s daily pill for obstructive sleep apnea (OSA) reduced the number of nightly breath-stopping events by 46.8%, smashing the primary endpoint of the randomized, placebo-controlled, double-blind LunAIRo study and setting up the company for a new drug application submission by early 2026.
Patients in the placebo arm scored just a 6.8% drop in OSA severity as assessed by the apnea-hypopnea index (AHI), a measure of the average number of times a patient either stops breathing or experiences shallow breathing per hour while sleeping, Apnimed announced in a July 23 release.
The company also reported that there were no serious adverse events related to the treatment, called AD109, and that all treatment-related adverse events were mild or moderate. LunAIRo enrolled 660 adult patients from across the U.S.
Though treatment lasted for a year, with the trial wrapping up in May, AHI scores for the primary endpoint were taken at the 26-week mark. The statistically significant drop in disease severity compared to placebo persisted to the end of the treatment period, Apnimed said.
The LunAIRo results come two months after Apnimed dropped top-line results from another pivotal phase 3 trial called SynAIRgy. That trial was similar to LunAIRo, enrolling 646 participants and testing their AHI scores after six months of nightly AD109 doses. SynAIRgy found a similarly significant drop in AHI of 55.6%.
“With two large phase 3 studies now demonstrating a consistent and significant efficacy profile for AD109, we are closer to delivering the first oral pharmacotherapy for over 80 million U.S. adults with OSA,” Apnimed CEO Larry Miller, M.D., said in the release. “We believe AD109, as a simple once-daily oral drug, has the potential to expand and reshape the treatment landscape.”
Apnimed also shared a selection of other results from LunAIRo, including that AD109 significantly improved oxygenation and that 22.5% of patients receiving the asset had their OSA completely controlled at the end of the trial, defined as an AHI score lower than five.
AD109 is a combination of aroxybutynin, a novel antimuscarinic, and atomoxetine, a noradrenaline reuptake inhibitor that is also used in attention-deficit/hyperactivity disorder. The compound targets the motor neurons that control breathing during sleep and boosts their activity so that throat muscles don’t relax, which is what causes breathing disruptions in patients with OSA.
If approved, AD109 would provide a far less cumbersome treatment for OSA, which is most often addressed by wearing a mask hooked up to a CPAP machine while sleeping. This device pumps air into the airway so that pressure doesn’t drop low enough for muscles to collapse.
Apnimed is already preparing for AD109’s commercial launch, tapping Pfizer veteran Graham Goodrich as chief commercial officer in January 2024.
Should it secure the FDA’s green light, AD109 would be the first prescription drug designed specifically for sleep apnea. Eli Lilly’s weight loss drug Zepbound (tirzepatide) became the first ever FDA-approved sleep apnea med in December 2024 but is only approved for adults with obesity.