Ethris, a German clinical-stage biotechnology company, has dosed the first patient in a Phase IIa clinical trial of its lead mRNA candidate, ETH47, which is designed to tackle one of the most common triggers of asthma flare-ups, i.e., respiratory viral infections.
The randomized, double-blind, placebo-controlled trial (ISRCTN21576805) , conducted by VirTus Respiratory Research Ltd. at St. Mary’s Hospital in London, will assess whether ETH47 can reduce asthma symptoms following a controlled rhinovirus challenge in adults with the condition. A total of 50 patients will be enrolled and randomized to receive either ETH47 or placebo, with the primary endpoint measuring changes in Lower Respiratory Symptoms Score (LRSS).
ETH47 development
Asthma exacerbations are often triggered by respiratory viruses, leading to acute episodes that may require emergency care. ETH47 takes a different approach from most current treatments, which focus on managing inflammation or relieving symptoms. The therapy uses stabilized, non‑immunogenic mRNA to encode interferon lambda (IFNλ), a protein that boosts antiviral immunity in the airways. Delivered intranasally via Ethris’ proprietary lipid nanoparticle system, ETH47 aims to fortify the respiratory tract’s first line of defense against viral infections.
“Dosing the first patient in our Phase IIa trial marks a defining moment for Ethris,” said Dr. Thomas Langenickel, chief medical officer of Ethris. “By targeting viral infections upstream, ETH47 has the potential to fundamentally change asthma management and reduce the burden of acute attacks.”
Professor Sebastian Johnston of Imperial College London, emphasized the need for innovation: “There remains a significant unmet need for interventions that directly target viral triggers and boost antiviral defenses in the airways. This is precisely where ETH47 could make a real difference.”
The Phase IIa study follows encouraging Phase I results in 40 healthy volunteers, where ETH47 was safe, well-tolerated, and showed strong localized antiviral activity. No systemic exposure to the mRNA, IFNλ, or lipid nanoparticle was detected, signifying a minimized potential for off-target effects. Researchers observed dose-dependent production of IFNλ in the nasal lining and activation of antiviral genes, supporting the candidate’s proposed mechanism of action.
Broader Respiratory and Pandemic Potential
ETH47 was developed using Ethris’ Stabilized Non‑Immunogenic mRNA (SNIM RNA) platform and its Stabilized NanoParticle (SNaP) lipid nanoparticle delivery system. The drug’s virus‑ and mutation‑independent mechanism of action makes it a potential tool against a wide range of seasonal and emerging respiratory viruses.
In May, Ethris received a €10 million EU4Health grant to support NoVir, a program exploring ETH47’s potential beyond asthma. Projects under NoVir include studies in chronic obstructive pulmonary disease (COPD) patients, trials in healthy volunteers infected with influenza, and preclinical testing against viruses such as paramyxoviruses, orthomyxoviruses, coronaviruses, and bunyaviruses. Research will also investigate ETH47’s application for intravaginal, ocular, and systemic infections, as well as its potential to enhance existing antiviral treatments.
NoVir is being conducted in collaboration with the Technical University of Munich and Aarhus University.
