Vaxart, a privately held company developing vaccines that are administered by tablet rather than by injection, today announced that the company is accelerating its Ebola tablet vaccine program. Following a recent meeting with the U.S. Food and Drug Administration (FDA), Vaxart anticipates commencing human clinical trials in the first quarter of 2015.
In a preclinical study conducted at the United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Vaxart’s Ebola vaccine candidate demonstrated protective efficacy against a challenge with Ebola virus. USAMRIID, the lead military medical research laboratory for the Defense Threat Reduction Agency’s Joint Science and Technology Office for Chemical and Biological Defense, protects military personnel from biological threats and investigates disease outbreaks or threats to public health.
Vaxart’s Ebola vaccine candidate is designed to generate an immune response against the Ebola GP protein. This immune response has been shown by other researchers to be protective against challenge with Ebola when administered by injection in non-human primates. The Vaxart vaccine does not contain any whole killed or attenuated (weakened) Ebola virus and therefore cannot cause an Ebola infection.
Vaxart’s Ebola vaccine candidate is based on its proprietary oral vaccine delivery platform: a disabled virus (non-replicating adenovirus type 5, or Ad5) that co-delivers the gene for the specific vaccine antigen and the gene for a TLR3 ligand that functions as an adjuvant to amplify the immune response. The platform can be used to induce, via oral administration, a selective and robust immune response to any recombinant antigen regardless of pre-existing immunity to Ad5.
Importantly, Vaxart tablet vaccines can be held at room temperature for more than a year, thus reducing or even eliminating the need for cold storage, a significant advantage in distribution and administration of the vaccines in areas with limited infrastructure.
“The alarming spread and tragic human toll of the current Ebola outbreak underscores the importance of being able to develop, manufacture and distribute safe and effective vaccines in the shortest possible time,” said Vaxart CEO Wouter Latour, MD. “Our platform technology allows us to respond to new pathogens by creating new vaccine candidates in a matter of days. We can use the same manufacturing and tableting process across all our vaccines, allowing us to move very efficiently from concept to final product. Finally, our room-temperature stable tablets are ideally suited to address the unique challenges on the ground in many affected areas. Accordingly, we have accelerated our Ebola vaccine program utilizing all available resources.”
Vaxart recently announced phase 1 clinical results for its H1N1 influenza tablet vaccine candidate based on the same Ad5 platform, demonstrating an excellent clinical safety profile and immunogenicity comparable to marketed influenza vaccines as determined by hemagglutinin inhibition assay (HAI), the accepted correlate of protection for influenza. The Vaxart H1N1 influenza vaccine also generated strong mucosal and T-cell responses in more than 90 percent of recipients, suggesting it may provide broader protection than conventional injectable vaccines.