NasoVAX Found to Induce Stable Antibodies Over 6 Months

A clinical-stage immunotherapeutics company announced additional positive data from a Phase 2a clinical study of its NasoVAX intranasal influenza vaccine candidate.

This limited, randomized Phase 2a study compared a monovalent NasoVAX vaccine against an H1 strain of influenza (A/California/04/2009) to intranasal placebo in 60 healthy adults across 3 dose ranges (109 virus particles (vp), 1010 vp and 1011vp).

In a parallel open-label study, a similar population of 20 subjects were given Fluzone, a licensed injectable influenza vaccine.  Blood samples from both studies were tested and the lab was blinded to treatment assignment.

Previously, Altimmune’s NasoVAX was found to be well-tolerated at all doses, resulted in 100 percent seroprotection at the two highest dose levels and elicited influenza neutralizing antibodies similar to Fluzone, which is a licensed injected influenza vaccine. 

NasoVAX also demonstrated the ability to elicit a significant T cell immune response as compared to Fluzone.   

These clinical study subjects were followed for an additional 6 months after vaccination to assess the durability of the antibody response.   

The new NasoVAX data demonstrate:

• a durable, dose-dependent protective immune response,
• significant mucosal immune response one month after vaccination compared to both placebo and Fluzone, and
• a clean safety profile.

Additionally, an influenza-specific mucosal antibody (IgA) response was demonstrated at all dose levels of NasoVAX, with the highest responses in the highest dose groups, while Fluzone and placebo groups demonstrated no response.   

Mucosal antibodies can be found in tears, saliva and nasal mucous and are the first line of immune defense thereby preventing influenza infection at the site of entry in the respiratory tract.

Serum antibody levels for NasoVAX were very stable through at least 6 months (the last time point tested), unlike Fluzone where antibody levels declined by over 50 percent during that time period.   

“The fact that NasoVAX induced antibodies that were very stable over the 6 month follow up period may indicate a higher likelihood of protection throughout the entire flu season,”

William J. Enright, president and chief executive officer of Altimmune said in a press release. 

"NasoVAX is egg-free and needle-free.  We believe that an intranasally administered flu vaccine will be preferred by patients over traditional injected vaccines.”   

“Additionally, because NasoVax is grown in cell culture instead of in chicken eggs, we believe NasoVax will eliminate the risk of egg allergies with the potential to enable us to more quickly mass produce vaccine at scale and have potentially better matches to annual circulating strains.”

“We believe NasoVAX to be a very differentiated and superior vaccine to those available on the market right now."

Altimmune will present the full data-set from this NasoVAX Phase 2 trial at IDWeek, an international infectious disease conference, in October of this year.

Altimmune is a clinical-stage immunotherapeutics company focused on the development of products to stimulate robust and durable immune responses for the prevention and treatment of infectious disease.