Aer Therapeutics Announces Top-Line Results from its Phase 2a Proof-of-Concept Trial of Fexlamose in Chronic Obstructive Pulmonary Disease (“COPD”)

• 90 mg dose of fexlamose administered daily via nebulizer did not demonstrate improvement on trough FEV1, FVC and other spirometric measures with 28 days of dosing in moderate to severe COPD patients.
• Fexlamose did not demonstrate an overall reduction from baseline in Mucus Plug Segment Score (“MPSS”), an imaging biomarker measuring pharmacodynamics, target engagement and efficacy.
• Most respiratory adverse events, including COPD exacerbations, occurred in the fexlamose arm, and treatment discontinuation was much more frequent on fexlamose than placebo.
  

RESEARCH TRIANGLE PARK, N.C., Oct. 30, 2026 (GLOBE NEWSWIRE) -- Aer Therapeutics, Inc., a biopharmaceutical company that is developing fexlamose for the treatment of serious respiratory diseases such as COPD, asthma, non-CF bronchiectasis and cystic fibrosis, announced today that its Phase 2a proof-of-concept study evaluating 90 mg of fexlamose administered daily via nebulizer in moderate-to-severe COPD patients did not achieve its primary or secondary endpoints of efficacy. Fexlamose was also associated with a higher incidence of respiratory adverse events compared with placebo, including COPD exacerbations and adverse events leading to treatment discontinuation.

AER-01-002 (NCT06731959) was a randomized, double-blind, placebo-controlled parallel group study designed to evaluate the efficacy and safety of fexlamose 90 mg in comparison to placebo. The study was conducted in Australia, New Zealand, United Kingdom, Poland, Spain and Bulgaria, and enrolled 119 moderate-to-severe COPD patients, with over 75% of patients with either severe or very severe airflow limitation as classified by their Global Initiative for Chronic Obstructive Lung Disease (GOLD) status.

John Fahy, MD, MSc, Founder and Chief Clinical Consultant, and Professor, Division of Pulmonary, Critical Care, Allergy and Sleep Medicine at the University of California, San Francisco (UCSF), commented, "I am deeply grateful for the investor support that enabled Aer’s Phase 2a clinical trial of fexlamose in COPD patients with mucus plugs. Although the primary endpoint was not met, this study yielded high-value data that will advance our understanding of mucus plug pathology in COPD and other lung diseases. I want to extend my sincere thanks to the Aer team, our clinical site investigators, and especially the trial participants for ensuring the timely completion of the trial."

“We are disappointed by the results of this proof-of-concept trial, but proud to have investigated the potential benefits of a muco-active drug like fexlamose in COPD,” said Thomas P. Mathers, Executive Chairman of Aer Therapeutics.

About Fexlamose

Pathologic mucus is characterized by excessive disulfide cross-linking between mucin polymers, leading to formation of mucus plugs that block airways. Mucus plugs are present in up to half of moderate-to-severe COPD and asthma patients, reducing lung function, impairing quality of life, and increasing mortality. However, there are currently no effective mucolytic treatments for these patients. In the US alone, over 5 million people with COPD and 1.5 million with asthma are affected by mucus plugs.

Fexlamose is an inhaled thiol-based therapeutic agent designed to liquify mucus plugs by cleaving the chemical disulfide bonds that thicken mucus.

About Aer Therapeutics, Inc.

Aer Therapeutics is a clinical-stage biopharmaceutical company developing fexlamose for muco-obstructive lung diseases like COPD, asthma, non-CF bronchiectasis and cystic fibrosis. The Company completed its Series A financing in 2022 and is supported by leading investors such as Orbimed, Canaan, Hatteras Venture Partners, Pappas Ventures, Alexandria Real Estate Equities and UCSF Foundation Investment Company.