Altesa BioSciences Reports Positive Phase 2 Vapendavir Challenge Study Results for COPD Exacerbations

Altesa BioSciences presented new clinical findings demonstrating that vapendavir, an investigational oral rhinovirus capsid inhibitor, reduced the inflammatory response and viral load in COPD patients infected with rhinovirus in a Phase 2a challenge study. The results were shared at the 2026 American Society for Microbiology (ASM) Microbe Conference and the 2026 American Thoracic Society International Conference (ATS).

The randomized, placebo-controlled study showed that vapendavir treatment blunted the elevation in inflammatory mediators and viral load. Compared to placebo, vapendavir reduced peak IFN-α2a levels by approximately 38%, peak IP-10 levels by approximately 50%, and peak IL-29 levels by approximately 67%. The study also demonstrated reduced viral load, reduced inflammation measured by several clinically relevant chemokines, and maintained small airway function as measured by oscillometry. Improved median time to symptom resolution was 5 days with vapendavir versus 8.5 days with placebo, as measured by E-RS. Patient-reported outcomes improved, including a decrease in the number of subjects with a clinically meaningful worsening in St. George's Respiratory Questionnaire. No safety or tolerability issues were identified.

The challenge model used was the only COPD rhinovirus challenge model globally, designed to reproduce upper and lower airway symptoms characteristic of community-acquired illness. The RV-16 strain used was less sensitive to vapendavir than approximately 85% of naturally circulating strains, suggesting observed clinical benefit should not overrepresent vapendavir's activity against typical real-world infections. Safety and tolerability of vapendavir have been established in approximately 700 healthy volunteers and patients with asthma or COPD across the development program.

Rhinovirus is responsible for approximately 50% of acute exacerbations of COPD, yet no approved rhinovirus treatment or vaccine currently exists. Vapendavir is a broad-spectrum antiviral that prevents the virus from entering human cells and reproducing, exhibiting potent activity across 97% of rhinoviruses and other respiratory enteroviruses.

Altesa recently enrolled the first patient in the Phase 2b CARDINAL clinical trial, a multinational randomized placebo-controlled study aiming to demonstrate that treatment of rhinovirus infections with vapendavir may improve upper and lower airway symptoms, reduce illness duration, and better maintain small airway lung function compared to placebo. The CARDINAL study will enroll 900 people with COPD in the US and UK and will run through Q4 2027. The trial is designed to reflect real-world care models, proactively identifying and supporting those at greatest risk. Participants will be monitored over time and, upon development of rhinovirus infection, randomized to receive one of two doses of vapendavir or placebo. The primary objective is to assess improvement in respiratory symptoms using established patient-reported outcomes, with additional endpoints evaluating time to symptom resolution, quality of life, healthcare resource utilization, and lung function.