Inhaled Antibody Therapy for RSV Moving Forward

A new inhaled antibody medication by Inhalon Biopharma, Inc. is moving forward in its clinical trials the prevention of acute respiratory infections.

The first-in-class inhaled antibody medication, IN-002, has completed IND-enabling studies for respiratory syncytial virus (RSV), according to a news release.

Inhalon plans to begin a human challenge study in 2026.

To support this next phase, Inhalon has partnered with hVIVO, a leader in human challenge trials, to conduct the Phase 2a trial.

RSV continues to be a major public health concern, especially for vulnerable populations. It’s a significant cause of lower respiratory infections in children and poses risks to the elderly and adults with chronic health issues.

Globally, it affects about 33 million people each year, leading to around 4 million hospitalizations and approximately 101,000 deaths in children under five.

Although many RSV vaccines have been approved recently, there remains a critical need for effective antiviral treatments for those who have the virus.

Current projections suggest RSV vaccine adoption will reach only 35% of original expectations.

While RSV prevention options are limited, Inhalon’s new approach could help fill the gap.

Currently, the only other antibody treatment for RSV prevention is nirsevimab (Beyfortus), an injectable monoclonal antibody designed to prevent severe RSV disease in infants and young children.

Unlike vaccines that stimulate the immune system to produce long-term immunity, monoclonal antibodies provide passive immunity, meaning they directly supply the protective antibodies.

According to the CDC, nirsevimab does not offer long-term immunity but protects infants during their most vulnerable stages. As children age, the severity of RSV symptoms typically decreases.

Inhalon’s inhaled antibody therapy aims to address this need, the release said. Its RSV candidate is part of a more broad effort to develop therapies that deliver therapeutic antibodies directly to the site of infection in the airways using a handheld nebulizer.

The nebulizer bypasses the need for oral or intravenous administration.

Animal studies have also shown this method to be more effective at treating respiratory infections, as well as reduce healthcare costs and ease the burden of care on patients.

“The treatment paradigm for respiratory infections is ripe for disruptive innovation,” John Whelan, president and CEO of Inhalon Biopharma, said. “Preventive immunizations are underutilized, especially in RSV, where vaccine usage is now expected to be one-third of original estimates.

As many as 30-50% of immunized patients experience breakthrough infection, leaving vulnerable populations – infants, toddlers, and the elderly – at high risk of severe infection. There are currently no approved treatments for the underlying RSV infection.”

He added that the potential therapy’s inhaled antibody treatment approach “not only targets the underlying pathophysiology of RSV and other respiratory infections, but also provides painless, self-administration by patients in their own homes, potentially reducing hospitalizations.”

Previous clinical data comparing Inhalon’s inhaled antibody therapy with an approved intravenous antibody treatment found that Inhalon’s antibodies maintained full activity after nebulization.

The inhaled treatment was able to distribute uniformly throughout the respiratory tract, including the deep lung.

The study also showed that subjects receiving inhaled doses had 30-fold to 100-fold higher concentrations of the antiviral antibody in their respiratory tracts compared to those receiving intravenous doses, even though the inhaled group received up to 90% fewer antibodies.

As Inhalon prepares for its human challenge study in 2026, the company continues to explore broader applications for its innovative technology.