Apnimed has filed an S-1 with the US Securities and Exchange Commission (SEC) laying out the terms for its initial public offering (IPO).
The Cambridge, Massachusetts-based biotech plans to offer 10 million shares priced between $14 and $16. At the midpoint of that range, Apnimed expects to net roughly $134.6 million, rising to about $155.5 million should underwriters fully exercise their option on an extra 1.5 million shares.
The company first signalled its intention to go public earlier this month. The filing with SEC confirms it is following a growing group of biotechs testing investor appetite for the public markets this year.
A pill for an underserved market
Apnimed’s lead candidate is AD109, commercially known as Oxnimbi. Rather than propping the airway open mechanically the way a CPAP machine does, Oxnimbi is designed to boost activity in the neuromuscular pathways that keep the upper airway from collapsing during sleep. This mechanism of action targets what the company describes as the underlying neurobiological cause of obstructive sleep apnea (OSA).
“OSA is a highly prevalent condition, estimated to be affecting approximately 80 million people in the US between the ages of 30-69. We believe many people with OSA remain undiagnosed in part due to lack of awareness, but also because they seek to avoid current treatment options that they anticipate will be uncomfortable or unacceptable,” Apnimed wrote in its filing.
“We believe Oxnimbi, if approved, can be prescribed for most adults diagnosed with mild, moderate or severe OSA, including obese and non-obese patients. In the future, we may seek approval for Oxnimbi for adolescent and child patients as well. However, our current focus is on the treatment of the adult OSA population.”
Apnimed intends to put roughly $228.8 million toward regulatory costs and the potential commercial rollout of Oxnimbi. This funding draws on both the IPO proceeds and existing cash. The company reported a preliminary cash position of about $172.8 million as of the end of June 2026.
The US Food and Drug Administration (FDA) accepted Apnimed’s New Drug Application for Oxnimbi in July 2026. That filing followed two Phase III clinical trials, SynAIRgy (NCT05811247) and LunAIRo (NCT05813275), which both hit their primary endpoints.
If approved for use, Oxnimbi would be the first drug purpose-built for the general OSA population.
Eli Lilly’s Zepbound, which became the first FDA-approved drug for sleep apnea in December 2024, is only available to patients who also have obesity.
“Prescription drug development in the field of OSA is relatively novel, and until the approval of tirzepatide in 2024 for moderate to severe OSA in obese adults in combination with a reduced-calorie diet and increased physical activity, the FDA historically did not have well-established therapeutic endpoints for this indication,” the company highlighted.
“We believe the OSA market is ripe for disruption, similar to other disease markets that were transformed by the introduction of an effective oral therapy such as osteoporosis, erectile dysfunction, rheumatoid arthritis, multiple sclerosis, hepatitis C and others.”