Soligenix Announces Publication of Positive Data Describing Protection from Mucosal and Systemic Ricin Intoxication by Intradermal RiVax Administration
Preclinical data demonstrate the potential for intradermal delivery of RiVax(TM)
PRINCETON, N.J., June 25 /PRNewswire-FirstCall/ -- Soligenix,
Inc. (OTC Bulletin Board: SNGX) (Soligenix or the Company), a
late-stage biopharmaceutical company, announced today the
publication of an article in the June 2010 edition of Vaccine,
which describes protection from mucosal and systemic ricin
intoxication by intradermal administration of RiVax(TM), the
Company's vaccine against ricin toxin. The article was authored by
the Company's collaborators at the University of Texas Southwestern
Medical Center at Dallas (UT Southwestern) where the vaccine
originated. RiVax(TM) is currently being evaluated in Phase 1 human
safety and immunogenicity trials, as well as non-human primate
trials for efficacy.
The purpose of this study was to determine whether RiVax(TM)
administered by intradermal (ID) injection would be more
immunogenic and protective at lower doses. ID vaccination has
several practical advantages in protecting humans due to the ease
of administration, especially when using an ID gun, thereby
eliminating the need for needles and subsequent needle disposal. In
this publication, a comparison of ID and intramuscular (IM)
vaccination with or without an aluminum salt adjuvant at several
dose levels was investigated. The levels of anti-RiVax(TM)
antibodies generated in serum as well as the ability of the vaccine
to protect mice against ricin intoxication following systemic,
gastric gavage or aerosol challenges were determined.
The major findings to emerge from this study are as follows:
1. ID vs. IM administration of RiVax(TM) without adjuvant conferred equal
protection;
2. RiVax(TM) adsorbed to aluminum adjuvant was significantly better than
RiVax(TM) alone in eliciting specific antibodies, resulting in both
systemic and mucosal protection when 90-99% less vaccine was used;
3. Vaccination with RiVax(TM) adsorbed to aluminum adjuvant via the ID
route was significantly better than vaccination via the IM route at
protecting animals from ricin challenge, hence, smaller doses of
vaccine may be required when ID vaccination is used;
4. In comparing IM vs. ID vaccination with RiVax(TM) adsorbed to aluminum
adjuvant at low doses, the latter was more effective at protecting mice
from ricin-induced lung damage; and
5. RiVax(TM) specific antibody levels correlated with post challenge
survival.
"There have been many attempts to develop a prophylactic ricin
vaccine, using different preparations of the ricin holotoxin with
and without various adjuvants," stated Dr. Ellen Vitetta, Director
of the Cancer Immunobiology Center at UT Southwestern and senior
author of the study. "But none of these have been as extensively
studied as RiVax(TM) and none have looked at the ID vaccination
route."
"Since it is likely that a ricin vaccine would be used in an
emergency setting or by the military, the ease of ID vaccination
with jet injectors or similar devices with lower doses of vaccine
is rather important," stated Robert N. Brey, PhD, Chief Scientific
Officer of Soligenix. "It should also be noted that ID vaccination
was highly effective at protecting the lungs of the mice from ricin
aerosols, a likely route of delivery in the setting of
bioterrorism."
The article, entitled "Intradermal administration of RiVax(TM)
protects mice from mucosal and systemic ricin intoxication," was
authored by Drs. Marconescu, Smallshaw, Pop, Ruback, and Vitetta at
UT Southwestern. The research was funded directly by an NIH grant
to UT Southwestern and complements the NIH funding to Soligenix for
the development of RiVax(TM). The full article (Marconescu et. al.,
"Intradermal administration of RiVax protects mice from mucosal and
systemic ricin intoxication," Vaccine) is available online at
http://dx.doi.org/10.1016/j.vaccine.2010.05.045
About RiVax(TM)
RiVax(TM) is Soligenix's proprietary vaccine developed to
protect against exposure to ricin toxin and is the most advanced
vaccine in the company's portfolio. RiVax(TM) induces a protective
immune response in animal models of ricin exposure and is currently
being evaluated in humans. One human Phase 1 clinical trial has
been completed and a second trial is currently being
conducted.
Results of the first Phase 1 clinical trial of RiVax(TM)
indicated that the immunogen was safe and induced antibodies
anticipated to protect humans from ricin exposure. The outcome of
the study was published in the Proceedings of the National Academy
of Sciences (Vitetta et al., 2006, PNAS, 105:2268-2273). The second
trial, sponsored by UT Southwestern, is currently evaluating a more
potent formulation of RiVax(TM). Soligenix has developed processes
for large-scale manufacturing and is further establishing
correlates of the human immune response in non-human
primates.
The development of RiVax(TM) has been sponsored through a series
of overlapping challenge grants (UC1) and cooperative grants (U01)
from the NIH, granted to Soligenix and to UT Southwestern where the
vaccine originated. The second clinical trial is being supported by
a grant to UT Southwestern from the US Food and Drug
Administration's Office of Orphan Products Development. Soligenix
and UT Southwestern have collectively received approximately $25
million in grant funding from the NIH for development of RiVax(TM)
and related vaccine technologies.
About Ricin Toxin
Ricin toxin is a plant toxin thought to be a bioterror threat
because of its stability and high potency as well as the large
worldwide reservoir created as a by-product of castor oil
production. Exposure to ricin results in local tissue necrosis, and
general organ failure leading to death within several days of
exposure. The potential use of ricin toxin as a biological weapon
has been highlighted in an FBI terrorism report, which states that
"Ricin and the bacterial agent anthrax are emerging as the most
prevalent agents involved in WMD investigations" (http://www.fbi.gov/publications/terror/terrorism2002_2005.pdf).
There are currently no effective means to prevent the effects of
ricin intoxication. The successful development of an effective
vaccine against ricin toxin may act as a deterrent against the
actual use of ricin as a biological weapon and could be used in
rapid deployment scenarios in the event of a biological attack.
RiVax(TM) would potentially be added to the Strategic National
Stockpile and dispensed in the event of a terrorist attack.
About Soligenix, Inc.
Soligenix, Inc. (Soligenix) is a late-stage biopharmaceutical
company developing products to treat life-threatening side effects
of cancer treatments and serious gastrointestinal diseases, and
vaccines for certain bioterrorism agents. Soligenix's lead product,
orBec® (oral beclomethasone dipropionate or BDP), is a potent,
locally acting corticosteroid being developed for the treatment of
acute gastrointestinal Graft-versus-Host-Disease (GI GVHD), a
common and potentially life-threatening complication of
hematopoietic cell transplantation. orBec® is currently the
subject of a confirmatory Phase 3 clinical trial for the treatment
of acute GI GVHD and an NIH-supported, Phase 2, randomized,
double-blind, placebo-controlled trial in the prevention of acute
GVHD. Soligenix has also recently initiated an NIH-supported Phase
1/2 clinical trial of SGX201 in the prevention of acute radiation
enteritis. Additionally, Soligenix has a Lipid Polymer Micelle
(LPM(TM)) drug delivery technology for the oral delivery of
leuprolide for the treatment of prostate cancer and
endometriosis.
Through its Biodefense Division, Soligenix is developing
biomedical countermeasures pursuant to the Project BioShield Act of
2004. Soligenix's lead biodefense product in development is a
recombinant subunit vaccine called RiVax(TM), which is designed to
protect against the lethal effects of exposure to ricin toxin.
RiVax(TM) has been shown to be well tolerated and immunogenic in a
Phase 1 clinical trial in normal volunteers. RiVax(TM) is also the
subject of a $9.4 million NIH grant received by the Company
supporting development of new heat stable vaccines.
For further information regarding Soligenix, Inc., please visit
the Company's website at www.soligenix.com.
This press release contains forward-looking statements that
reflect Soligenix, Inc.'s current expectations about its future
results, performance, prospects and opportunities. Statements that
are not historical facts, such as "anticipates," "believes,"
"intends," or similar expressions, are forward-looking statements.
These statements are subject to a number of risks, uncertainties
and other factors that could cause actual events or results in
future periods to differ materially from what is expressed in, or
implied by, these statements. Soligenix cannot assure you that it
will be able to successfully develop or commercialize products
based on its technology, including orBec®, SGX201, RiVax(TM),
and LPM(TM), particularly in light of the significant uncertainty
inherent in developing vaccines against bioterror threats,
manufacturing and conducting preclinical and clinical trials of
vaccines, and obtaining regulatory approvals, that its cash
expenditures will not exceed projected levels, that product
development and commercialization efforts will not be reduced or
discontinued due to difficulties or delays in clinical trials or
due to lack of progress or positive results from research and
development efforts, that it will be able to successfully obtain
any further grants and awards, maintain its existing grants which
are subject to performance, enter into any biodefense procurement
contracts with the US Government or other countries, that the US
Congress may not pass any legislation that would provide additional
funding for the Project BioShield program, that it will be able to
patent, register or protect its technology from challenge and
products from competition or maintain or expand its license
agreements with its current licensors, or that its business
strategy will be successful. Important factors which may affect the
future use of orBec® for gastrointestinal GVHD include the
risks that: the FDA's requirement that Soligenix conduct additional
clinical trials to demonstrate the safety and efficacy of
orBec® will take a significant amount of time and money to
complete and positive results leading to regulatory approval cannot
be assumed; Soligenix is dependent on the expertise, effort,
priorities and contractual obligations of third parties in the
clinical trials, manufacturing, marketing, sales and distribution
of its products; orBec® may not gain market acceptance if it is
eventually approved by the FDA; and others may develop technologies
or products superior to orBec®. Factors affecting the
development and use of SGX201 and LPM(TM) are similar to those
affecting orBec®. These and other factors are described from
time to time in filings with the Securities and Exchange
Commission, including, but not limited to, Soligenix's reports on
Forms 10-Q and 10-K. Unless required by law, Soligenix assumes no
obligation to update or revise any forward-looking statements as a
result of new information or future events.
Source: Soligenix, Inc.
CONTACT: Company Contact, Evan Myrianthopoulos, Chief Financial
Officer
of Soligenix, Inc., +1-609-538-8200
Web Site: http://www.soligenix.com/
Posted: June 2010
