Ethris has announced topline data from a Phase 2a challenge study of ETH47 mRNA-based antiviral in adults with mild-to-moderate asthma. According to Ethris, the trial demonstrated that ETH47 “was safe, well tolerated and showed antiviral activity, with consistent numerical trend improvements versus placebo in lower respiratory symptom score (LRSS), mild exacerbations, upper respiratory symptoms (Jackson Cold Score, JCS), cold prevention and rescue medication use.”
The Phase 2a trial enrolled 50 adults with asthma who received either a single nasal dose of ETH47 or placebo one day prior to the rhinovirus challenge. ETH47 did not result in any systemic exposure or induction of anti-DMG-PEG antibodies, and no serious adverse events were reported, the company said, adding that local expression of interferon lambda was observed in “almost all” participants 6 hours post dose, as well as a 40-fold reduction in virus load on Day 2.
In September 2026, Ethris announced that it had secured €30 million in financing for continued development of ETH47 and several other candidates. The company says that it is currently working on development of a spray-dried formulation of ETH47 in addition to planning additional studies. Planned trials of ETH47 include a Phase 1 MAD study in asthma and COPD patients; a Phase 2a challenge study in COPD patients, and Phase 2b trials in both asthma and COPD.
Ethris CEO Carsten Rudolph commented, “These results confirm ETH47’s mechanism of action and target engagement in asthma patients. We gave a single dose in this first patient study and still observed consistent signals on top of standard-of-care inhaled therapy. The clear relationship between exposure and effect will inform dose and regimen optimization in the next study. That trial will focus on asthma patients as well as those with chronic obstructive pulmonary disease, who also carry a high burden of virus-triggered exacerbations.”
Read the Ethris press release
