Vaxart Announces Release – GuruFocus.com
A preclinical study in hamsters showed both a reduction in virus and in transmission
Phase 1 data measuring cross-reactivity are also included in the publication
SOUTH SAN FRANCISCO, Calif., May 19, 2022 (GLOBE NEWSWIRE) — Science Translational Medicine published the results of a preclinical hamster transmission study led by Duke University that found that Vaxart’s oral COVID-19-only vaccine candidate S (VXRT) inhibited the transmission of SARS-CoV-2. The report also outlines updated results from Vaxart’s Phase I clinical trial which suggest that Vaxart’s other vaccine candidate, one targeting both the S and N proteins, may be effective against a range of diverse coronaviruses. .
The study compared various measures of immunity and viral shedding in cohorts of hamsters immunized with Vaxart’s S-only vaccine candidate (administered orally and intranasally), an intramuscular protein vaccine control and a placebo. Vaccinated hamsters were then infected with high doses of SARS-CoV-2 to create a breakthrough vaccine and exposed to naïve animals during the breakthrough period. The study authors concluded that the S-only construction of Vaxart “reduced disease and decreased airborne transmission in a hamster model.”
The publication also reported results from the Phase I clinical study of Vaxart’s S+N vaccine candidate showing that it stimulated SARS-CoV-2-specific IgA antibodies in saliva and nasal specimens from human subjects and reacted crosswise to many different coronaviruses that are more divergent than the circulating variants of SARS-CoV-2.
“The publication of these results in a highly respected peer-reviewed journal such as Science Translational Medicine underscores the potential value of Vaxart’s COVID-19 oral vaccine platform in solving multiple aspects of the COVID-19 pandemic,” said Dr. Sean Tucker, Chief Scientific Officer of Vaxart and lead author of the publication.
S-only data from the preclinical hamster transmission study was originally reported last October in the non-peer-reviewed journal bioRxiv. Vaxart first reported the potential cross-reactive properties of its S+N vaccine candidate in May 2021. The new Science Translational Medicine The publication includes additional details regarding IgA antibody responses in human subjects.
Vaxart has moved into phase II clinical trials with the S vaccine candidate only and expects to report those results later this year. Vaxart has also completed and published preliminary Phase I results of its S+N vaccine candidate. As previously reported, the company plans to compare S-only and S+N candidate vaccines and decide which approach offers the best way forward for its COVID-19 vaccine development program, particularly in the face of emerging variant strains.
Preclinical study results conducted by Duke University, Lovelace Biomedical, and Vaxart demonstrated that Vaxart’s S-only vaccine candidate stimulates both mucosal IgA and serum IgG antibodies and can reduce both SARS- CoV-2 and airborne transmission. Decreasing transmission is important to protect unvaccinated people, including the nearly 34% of Americans who are not fully vaccinated.1
“Recent outbreaks of COVID-19 variants have shown us that vaccinated people who are infected with SARS-CoV-2 can spread the virus to unvaccinated members of their family and community, thereby contributing significantly to risk. for public health,” said Dr. Stephanie Langel, a scientist and medical instructor at Duke University and first author of the publication. “A vaccine that protects against infection and reduces transmission would provide significant personal and public health benefits. Additionally, an oral vaccine has the potential to address vaccine hesitancy in people who are averse to injection, which could help increase overall vaccination rates.
Phase I study
In the Phase I study, subjects with at least a two-fold increase in virus-specific IgA also showed an increase in IgA antibodies that cross-reacted with a variety of other coronaviruses. This broad cross-reactivity has the potential to provide increased protection against COVID-19 variants compared to injected vaccines that largely stimulate serum IgG responses. Phase I study data also demonstrated that Vaxart’s S+N vaccine candidate stimulates robust T cell responses, particularly CD8+ T cells.
The Phase I clinical study was designed to evaluate the safety and immunogenicity of Vaxart’s COVID-19 S+N oral vaccine candidate in 35 subjects. Participants received a single high dose (n=15), a single low dose (n=15) or two low doses (n=5) of the vaccine. IgA levels in saliva and nasal samples were assessed 29 days after vaccination. More than half (54%) of subjects had at least a two-fold increase in IgA antibodies in their saliva or nasal samples. The responses were similar for the S and N proteins as well as for the receptor binding domain. Subjects with at least a two-fold increase in virus-specific IgA in saliva or nasal specimens also showed an increase in cross-reactive IgA that bound to the spike proteins of the four endemic strains of coronavirus as well as the coronavirus of the Middle East respiratory syndrome (MERS-CoV) and SARS-CoV-1. The responses observed did not differ between the different doses.
1 US Centers for Disease Control and Prevention. COVID-19 vaccination in the United States. Available at: https://covid.cdc.gov/covid-data-tracker/#vaccinations_vacc-total-admin-rate-total
Vaxart is a clinical-stage biotechnology company developing a range of oral recombinant vaccines based on its proprietary delivery platform. Vaxart vaccines are designed to be administered using tablets that can be stored and shipped without refrigeration and eliminate the risk of needle stick injury. Vaxart believes that its proprietary tablet vaccine delivery platform is suitable for delivering recombinant vaccines, positioning the company to develop oral versions of currently marketed vaccines and to design recombinant vaccines for new indications. Vaxart’s development programs currently include vaccines in tablet form designed to protect against coronavirus, norovirus, seasonal influenza and respiratory syncytial virus (RSV), as well as a therapeutic vaccine against human papillomavirus (HPV), Vaxart’s first immuno-oncology indication. Vaxart has filed extensive domestic and international patent applications covering its proprietary technology and designs for oral vaccination using adenoviruses and TLR3 agonists.
Note Regarding Forward-Looking Statements
This press release contains forward-looking statements that involve substantial risks and uncertainties. All statements, other than statements of historical facts, included in this press release regarding Vaxart’s strategy, outlook, plans and objectives, results of preclinical and clinical trials, commercialization agreements and licenses, as well as that management’s beliefs and expectations are forward-looking statements. These forward-looking statements may be accompanied by words such as “should”, “believe”, “could”, “potential”, “will”, “expect”, “anticipate”, “plan” and other words and conditions of use. similar meaning. Examples of such statements include, but are not limited to, statements relating to Vaxart’s ability to develop and commercialize its product candidates, including its vaccine booster products; Vaxart’s expectations regarding clinical results and trial data; and Vaxart’s expectations regarding the efficacy of its product candidates. Vaxart may not actually achieve the plans, achieve the intentions or meet the expectations or projections disclosed in any forward-looking statements, and you should not place undue reliance on such forward-looking statements. Actual results or events could differ materially from the plans, intentions, expectations and projections disclosed in the forward-looking statements. Various important factors could cause actual results or events to differ materially from Vaxart’s forward-looking statements, including uncertainties inherent in research and development, including the ability to achieve anticipated clinical results, start dates and/or or completion of clinical trials, dates of regulatory submission, dates of regulatory approval and/or initiation dates, as well as the possibility of new adverse clinical data and further analysis of existing clinical data; the risk that clinical trial data will be subject to differing interpretations and assessments by regulatory authorities; whether regulatory authorities will be satisfied with the design and results of clinical studies; decisions of regulatory authorities impacting labeling, manufacturing processes and safety that could affect the availability or commercial potential of any product candidates, including the possibility that Vaxart’s product candidates may not be approved by the FDA or non-US regulatory authorities; that, even if approved by the FDA or non-US regulatory authorities, Vaxart’s product candidates may not achieve widespread market acceptance; that a Vaxart collaborator may not reach the development and commercial milestones; that Vaxart or its partners may experience manufacturing problems and delays due to events within or beyond the control of Vaxart or its partners; production difficulties, particularly in scaling up initial production, including difficulties with production costs and yields, quality control, including product candidate stability and quality assurance testing, shortages of qualified personnel or key raw materials, and compliance with strictly enforced federal, state, and foreign regulations; that Vaxart may not be able to obtain, maintain and enforce necessary patents and other intellectual property protection; that Vaxart’s capital resources may be insufficient; Vaxart’s ability to resolve outstanding legal issues; Vaxart’s ability to obtain sufficient capital to fund its operations on terms acceptable to Vaxart, if any; the impact of government health care proposals and policies; competitive factors; and other risks described in the “Risk Factors” sections of Vaxart’s quarterly and annual reports filed with the SEC. Vaxart undertakes no obligation to update forward-looking statements, except as required by law.
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