Altesa BioSciences Details Positive Topline Vapendavir Results from Phase 2 Placebo-Controlled Rhinovirus Challenge Study in COPD Patients

Antiviral improved overall patient-reported measures of both upper, lower respiratory symptoms, shortened overall course of illness

COLLEGE PARK, Ga., May 7, 2025 /PRNewswire/ -- Altesa BioSciences today announced positive topline results from its Phase 2 placebo-controlled study examining the effects of vapendavir in COPD patients challenged with rhinovirus.  In this study, treatment with vapendavir improved overall patient-reported measures of both upper and lower respiratory symptoms and led to a shortened overall course of illness.  These positive effects were supported by a reduced level and faster resolution of viral loads in the respiratory system of participants treated with vapendavir.

"This is the first study that has shown that an antiviral for rhinovirus infection, the most common cause of COPD exacerbations, can have a positive impact on upper and lower respiratory symptoms. This effect has the potential to reduce the severity of exacerbations or even prevent exacerbations of their disease, which can be devastating for these patients," said Kate Knobil, MD, chief medical officer of Altesa and former chief medical officer of GSK.  "Vapendavir demonstrated a consistent beneficial effect across numerous important parameters – suggesting this medicine could become a transformative new therapy for the more than sixteen million Americans and hundreds of millions around the world who daily suffer with COPD."  

"Rhinovirus infection is the most commonly identified cause of exacerbations among COPD patients – accounting for more than 45% of these flare-ups," said Dr. Brett Giroir, CEO of Altesa BioSciences and former US Assistant Secretary for Health and former Acting FDA Commissioner. "Our vision is to treat these viral infections with a safe and effective oral pill, which will stop the virus in its tracks before it can cause devastating consequences for patients," he continued. "If we are successful, not only will we save lives and improve the quality of life for patients, but also potentially save billions of dollars in health care expenditures each year."

Vapendavir, taken orally in pill form, is a broad-spectrum antiviral medicine that prevents rhinoviruses and related viruses from entering human cells and reproducing. It exhibits potent activity across 97% of rhinoviruses tested and other respiratory enteroviruses. Vapendavir is the only direct-acting antiviral medicine targeting rhinovirus now in human clinical trials.  Altesa BioSciences holds exclusive global rights to develop, manufacture, and commercialize vapendavir.

Study details

Altesa's rhinovirus challenge study was conducted by VirTus Respiratory Research Ltd. in London, United Kingdom, co-led by Professor Sebastian Johnston and Dr. Michael Edwards. With their collaborators at Imperial College London and St. Mary's Hospital, VirTus is the only company in the world to conduct such studies in COPD – and Johnston has done so safely since 2006.

Unlike many other challenge studies for other viral illnesses, our challenge model was designed to mimic as closely as possible the experience of COPD patients in the real world, starting treatment only when their symptoms start to worsen.  Participants did not receive vapendavir or placebo until they self-reported the onset of symptoms; furthermore, they were not isolated or confined in the clinic during the study – they went home after visits to live in their normal environment.

Participants in the study had a diagnosis of Stage 2 COPD and met specific criteria to ensure that the rhinovirus infection would only result in a temporary worsening of their illness. Participants generally developed an upper respiratory illness on the second day after challenge, followed by worsening of lower respiratory symptoms.  Vapendavir treatment began after the onset of clinical illness and continued for a total of seven days.   Vapendavir was well tolerated and appeared safe; significantly, there were more adverse events and more severe adverse events in the placebo group than in those treated with vapendavir.

More detailed results from Altesa's Challenge Study will be submitted for presentation at a future medical congress.

About Vapendavir
Vapendavir, taken orally in pill form, is an antiviral medicine with potent activity against 97% of rhinoviruses tested and other respiratory enteroviruses.  It prevents the virus from entering human cells as well as preventing it from reproducing. Vapendavir is currently in advanced clinical trials for the treatment of rhinovirus infections in people living with COPD.  Vapendavir has a similar mechanism of action to the FDA approved HIV capsid inhibitor, lenacapavir marketed by Gilead Sciences

About COPD
Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease that worsens over time. More than 16.4 million Americans, or 6.6% of U.S. adults, suffer with COPD, which is now among the leading causes of death in the US and globally.  Those with limited financial resources, especially those in urban and rural areas, are often diagnosed late, which is associated with worse overall outcomes.

About Altesa BioSciences, Inc.
Altesa BioSciences is a clinical-stage pharmaceutical company dedicated to developing new treatments for age-old threats to human health: high-consequence viral infections. These infections are particularly severe in vulnerable people, including those with chronic health conditions, like lung diseases, as well as the elderly and many people in underserved communities. 

About VirTus Respiratory Research Ltd
VirTus Respiratory Research Ltd is a contract research organization co-led by Professor Sebastian Johnston and Dr. Michael Edwards, both also of Imperial College London, United Kingdom. VirTus' mission is to accelerate development of new approaches for treatment/prevention of respiratory viral infections, the major cause of acute attacks (exacerbations) of chronic lung diseases including asthma, COPD and bronchiectasis. VirTus conducts pre-clinical studies as well as early clinical studies using their unique human virus challenge studies to help bring new therapies to the clinic.

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SOURCE Altesa Biosciences Inc.