SOUTH SAN FRANCISCO, Calif.,
July 29, 2021 /PRNewswire/
-- Vaxart, Inc. (Nasdaq: VXRT)
today announced that it has shown for the first
time in clinical trials that its oral tablet vaccine platform
successfully boosted immune responses
in subjects previously vaccinated with a Vaxart oral
vaccine more than a year earlier.
Vaxart is a clinical-stage biotechnology company developing oral
vaccines that are administered by tablet rather than by
injection. Vaxart's programs are based on its proprietary
oral vaccine platform called VAAST.
"These results are very important because they support our
belief that our oral tablet vaccines have the potential to be
used repeatedly for indications that may require an annual
boost, such as flu, COVID-19, or norovirus," said Andrei Floroiu, Vaxart's Chief Executive
Officer. "We are excited by these findings and by the
implications for all of our vaccines."
"Using our oral norovirus vaccine candidate, we successfully
boosted the immune responses of those previously vaccinated with
our platform," said Dr. Sean
Tucker, Vaxart's founder and Chief Scientific Officer. "We
believe these results could have implications for the other
vaccines we are developing, including our oral COVID-19 vaccine
tablet, because they are all based on the same platform and use the
same vector.
"Moreover," Dr. Tucker said, "this clinical evidence has the
potential to differentiate our vaccines from
injectable vector-based vaccines. Typically, when
you inject viral vector-based vaccines, they generate immune
responses against the against the viral vector as well as the
intended antigens.
"Anti-vector antibodies from the injected vaccine immune
response may prevent the viral vector from serving as a
boosting agent. Our norovirus trial results suggest that
Vaxart's vaccines may not be hampered by certain antibody
response challenges that can occur with injectable viral
vector-based vaccines."
The data came from Vaxart's 12-subject Phase
1b blinded study evaluating the ability of its
norovirus vaccine to boost immunogenicity. Study
participants were initially vaccinated with Vaxart's oral
norovirus vaccine in late 2019 and were vaccinated again
between February and April 2021.
All seven participants who had been previously
immunized with the oral norovirus vaccine elicited a similar broad
range of immune responses to norovirus as the five
subjects that had not received a prior oral vaccine
dose.
"We will continue to evaluate the capability of our norovirus
and COVID-19 vaccine candidates to be used repeatedly as boosters
to extend protection in those previously vaccinated with Vaxart
candidate vaccines."
Key metrics identified in the boosting study were as
follows:
- Serum antibody blocking titer 50, a surrogate neutralizing
antibody measurement, increased in both previously vaccinated
and unvaccinated subjects by similar amounts.
- Antibody secreting B cell (ASC) responses to
norovirus VP1 measured seven days post-boost were no different
than those in subjects receiving the vaccine for the first
time.
- Serum IgG and IgA antibody responses were significantly
elevated 29 days post-boost immunization, with no difference
in titer between subjects that had received a prior oral norovirus
vaccine and those who had not previously been
vaccinated.
About Vaxart
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 to deliver
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 tablet vaccines designed to protect
against coronavirus, norovirus, seasonal influenza, and respiratory
syncytial virus (RSV), as well as a therapeutic vaccine for human
papillomavirus (HPV), Vaxart's first immuno-oncology
indication. Vaxart has filed broad domestic and international
patent applications covering its proprietary technology and
creations for oral vaccination using adenovirus 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, prospects, plans and
objectives, results from pre-clinical and clinical trials,
commercialization agreements and licenses, and beliefs
and expectations of management are forward-looking statements.
These forward-looking statements may be accompanied by such words
as "should," "believe," "could," "potential," "will," "expected,"
"plan," and other words and terms of similar meaning. Examples of
such statements include, but are not limited to, statements
relating to the receipt by 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 with respect to the
effectiveness of its product candidates. Vaxart may not actually
achieve the plans, carry out the intentions, or meet the
expectations or projections disclosed in the forward-looking
statements, and you should not place undue reliance on these
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 the forward-looking statements that
Vaxart makes, including uncertainties inherent in research and
development, including the ability to meet anticipated
clinical endpoints, commencement and/or completion dates for
clinical trials, regulatory submission dates, regulatory
approval dates, and/or launch dates, as well as the possibility of
unfavorable new clinical data and further analyses of existing
clinical data; the risk that clinical trial data are subject to
differing interpretations and assessments by regulatory
authorities; whether regulatory authorities will be satisfied with
the design of and results from the clinical studies; decisions by
regulatory authorities impacting labeling, manufacturing processes,
and safety that could affect the availability or commercial
potential of any product candidate, including the possibility
that Vaxart's product candidates may not be approved by
the FDA or non-U.S. regulatory authorities; that, even if approved
by the FDA or non-U.S. regulatory
authorities, Vaxart's product candidates may not achieve
broad market acceptance; that a Vaxart collaborator may not attain
development and commercial milestones; that Vaxart or its partners
may experience manufacturing issues and delays due to events
within, or outside of, Vaxart's or its partners' control;
difficulties in production, particularly in scaling up initial
production, including difficulties with production costs and
yields, quality control, including stability of the product
candidate 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 patent and
other intellectual property protection;
that Vaxart's capital resources may be
inadequate; Vaxart's ability to resolve pending legal
matters; Vaxart's ability to obtain sufficient capital to
fund its operations on terms acceptable to Vaxart, if at all; the
impact of government healthcare 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 does not assume any obligation to update any
forward-looking statements, except as required by
law.
Contact
Vaxart Media
Relations:
Mark
Herr
Vaxart,
Inc.
(203)
517-8957
mherr@vaxart.com
View original content to download
multimedia:https://www.prnewswire.com/news-releases/vaxart-reports-boosting-immune-responses-in-subjects-previously-vaccinated-by-a-vaxart-vaccine-301344267.html
SOURCE Vaxart, Inc.