Enterprise Therapeutics has announced the publication of results from its phase 1 study of ETD001, a long-acting inhaled epithelial sodium channel (ENaC) blocker.
The study demonstrated that ETD001 was well tolerated in healthy individuals at doses higher than those predicted to be therapeutic, with findings consistent with preclinical models showing long-lasting improvements in mucociliary clearance.
The phase 1 trial evaluated the safety, tolerability and pharmacokinetics of ETD001 through single and multiple ascending inhaled doses. Results showed the treatment was well tolerated both at single doses and with repeat dosing twice daily for up to 14 days.
Unlike earlier inhaled ENaC blockers, ETD001 displayed a pharmacokinetic profile consistent with slow absorption from the lung into systemic circulation, suggesting prolonged retention in the lung and potential for extended duration of action. Importantly, blood potassium levels remained within normal limits at all doses tested, addressing a key safety concern associated with ENaC blockade in the kidney.
These findings align closely with preclinical data, which demonstrated a favourable safety profile and extended duration of action in the lung for more than 16 hours after a single inhaled dose. Enterprise is now conducting a phase 2 trial to assess whether 28 days of treatment with ETD001 can improve lung function in people with cystic fibrosis, with headline data expected in early 2026.
Dr Henry Danahay, Head of Biology at Enterprise Therapeutics and lead author of the paper, said: “There is an urgent need for new therapies to treat mucus obstruction in the lungs of people with CF, and especially those who are genetically unsuited to CFTR modulators.
“We are passionate about working towards treatments that will benefit all people with cystic fibrosis and are excited to publish these promising results from our Phase 1 trial. We are grateful for everyone who took part in this trial, and for the people with cystic fibrosis that are enrolled in the ongoing Phase 2 trial of ETD001.”
Cystic fibrosis affects over 100,000 people worldwide, with average life expectancy of around 60 years. The condition is characterised by failed mucociliary clearance and mucus congestion in the lungs, leading to cycles of infection, inflammation and progressive decline in lung function. Inhibiting ENaC in the airways offers a potential route to restore airway mucus hydration and drive significant improvements in lung health.
