Cleveland BioLabs, Roswell Park Announce Publication of Studies Defining Role of Liver in Activity of Entolimod (CBLB502)

Cleveland BioLabs, Roswell Park Announce Publication of Studies Defining Role
of Liver in Activity of Entolimod (CBLB502)

BUFFALO, N.Y., May 1, 2013 (GLOBE NEWSWIRE) -- Cleveland BioLabs, Inc.
(Nasdaq:CBLI) and Roswell Park Cancer Institute (RPCI) today announced the
publication of studies identifying the liver as a key mediator of Entolimod's
tissue-protective and anticancer activities in Proceedings of the National
Academy of Sciences of the United States of America (PNAS), the official
journal of the United States National Academy of Sciences. The reported
studies were conducted by scientists at Roswell Park Cancer Institute and
Cleveland BioLabs (CBLI) in collaboration with researchers at Attagene, Inc.
and the Gamaleya Research Institute for Epidemiology and Microbiology in

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Entolimod is a Toll-like receptor 5 (TLR5) agonist currently under development
by CBLI as both a radiation countermeasure and a cancer agent. Previous work
showed that the biological effects of Entolimod stem from TLR5-mediated
activation of NF-kB, a transcriptional regulator that induces multiple genes
encoding tissue-protective factors, such as inhibitors of programmed cell
death, scavengers of reactive oxygen species, and cytokines that promote cell
proliferation and differentiation. The current studies were aimed at defining
the mechanism of systemic response to Entolimod at the molecular and cellular
levels. The results showed that the liver is a major primary target organ of
Entolimod. The specific responsiveness of one particular type of liver cell,
the hepatocyte, distinguishes TLR5 from other TLRs and provides plausible
explanation for superior pharmacological properties of Entolimod compared to
agonists of other TLRs.

A novel technique called Factorialâ„¢, developed by Attagene, was utilized to
define molecular signaling pathways modulated by Entolimod in the liver. This
technique made it possible to simultaneously monitor the activity of close to
50 inducible transcription factors in the liver of treated animals. In
addition to the NF-kB pathway, Entolimod treatment was found to activate
several other pro-survival and immunoregulatory signaling pathways in
hepatocytes, culminating in induction of secreted cytokines and recruitment of
immune cells to the liver. In several animal models tested, this led to
suppression of tumor cell growth in the liver regardless of whether the tumor
cells expressed TLR5. These results expand the potential anticancer
applications of Entolimod beyond treatment of TLR5-expressing primary tumors
to include prevention and/or treatment of metastases to the liver,
irrespective of the primary tumor's TLR5 status. The liver is among the most
common metastatic sites for several different types of cancer. Of particular
importance, while Entolimod treatment induced changes in the liver
microenvironment that counteracted tumor cell growth, it also made normal
liver cells resistant to a form of cell death commonly involved in
hepatotoxicity. This finding suggests that Entolimod may offer a new approach
for liver protection in a variety of clinical scenarios.

Finally, by showing that occlusion of hepatic blood circulation eliminated
Entolimod-mediated radioprotection of the hematopoietic system, the reported
work strongly suggests that exposure of liver cells to Entolimod is essential
for the drug's radioprotective and radiomitigating activity. Therefore,
factors secreted by responsive hepatocytes appear to be responsible, at least
in part, for the ability of Entolimod to protect and stimulate regeneration of
the hematopoietic system in irradiated animals. 

Andrei Gudkov, Ph.D., D.Sci., Chief Scientific Officer of Cleveland BioLabs,
Senior Vice President of Basic Science at RPCI and corresponding author of the
paper, commented: "Entolimod continues to pleasantly surprise us. The studies
reported in this publication represent the first comprehensive work on TLR5
signaling conducted in vivo. They provide new mechanistic insight into the
radioprotection, radiomitigation and anticancer activities of Entolimod,
strengthening both our understanding of the drug's ability to mitigate
radiation damage to the hematopoietic system and the hypothesis behind an
ongoing clinical study with the drug in advanced cancer patients at Roswell
Park Cancer Institute. Moreover, the previously unanticipated effects of
Entolimod on hepatocytes and the liver microenvironment defined in this work
suggest that prevention or treatment of liver metastases and protection of the
liver from various types of cell stress are additional areas of prospective
clinical application for Entolimod."

Jean Viallet, M.D., Chief Development Officer at Cleveland BioLabs, stated,
"The intense liver-directed immune response induced by Entolimod resulted in
the prevention of liver metastases in several experimental models.Several
types of human cancer show a strong predilection to metastasize to the
liver.The clinical implications are exciting, and our team is already
developing clinical trials to bring these new concepts to patients."

The work reported in the publication was supported by National Institutes of
Health Grants R01AI080446 and RC2AI087616 and by Cleveland BioLabs, Inc., as
well as by the Defense Threat Reduction Agency of the U.S. Department of
Defense under Contract HDTRA1-11-C-0008 (to Cleveland BioLabs, Inc.).

The PNAS publication can be found online at:

About Cleveland BioLabs, Inc.

Cleveland BioLabs, Inc. is a clinical-stage biotechnology company leveraging
deep mechanistic understanding of the cell death process, apoptosis, to
develop a robust pipeline of compounds primarily focused on oncology
applications and mitigation of radiation injury. The Company's lead compound
is being developed as both a radiation countermeasure and a cancer treatment.
The Company has two operating subsidiaries, Incuron, LLC, and Panacela Labs,
Inc., and strategic relationships with the Cleveland Clinic, Roswell Park
Cancer Institute, the Children's Cancer Institute Australia and the Armed
Forces Radiobiology Research Institute. To learn more about Cleveland BioLabs,
Inc., please visit the Company's website at

About Roswell Park Cancer Institute:

The mission of Roswell Park Cancer Institute (RPCI) is to understand, prevent
and cure cancer. RPCI, founded in 1898, was one of the first cancer centers in
the country to be named a National Cancer Institute-designated comprehensive
cancer center and remains the only facility with this designation in Upstate
New York. The Institute is a member of the prestigious National Comprehensive
Cancer Network, an alliance of the nation's leading cancer centers; maintains
affiliate sites; and is a partner in national and international collaborative
programs. For more information, visit RPCI's website at, call 1-877-ASK-RPCI (1-877-275-7724) or email

This press release contains certain forward-looking information about
Cleveland BioLabs that is intended to be covered by the safe harbor for
"forward-looking statements" provided by the Private Securities Litigation
Reform Act of 1995, as amended. Forward-looking statements are statements that
are not historical facts. Words such as "expect(s)," "feel(s)," "believe(s),"
"will," "may," "anticipate(s)" and similar expressions are intended to
identify forward-looking statements. These statements include, but are not
limited to, statements regarding our ability to successfully develop and
commercialize our therapeutic products; our ability to expand our long-term
business opportunities; the conduct and results of our various clinical
trials; financial projections and estimates and their underlying assumptions;
and future performance. All of such statements are subject to certain risks
and uncertainties, many of which are difficult to predict and generally beyond
the control of the Company, that could cause actual results to differ
materially from those expressed in, or implied or projected by, the
forward-looking information and statements.

These factors include, among others, the Company's failure to successfully and
timely develop new products; the Company's collaborative relationships and the
financial risks related thereto; the Company's ability to comply with its
obligations under license agreements; the risks inherent in the early stages
of drug development and in conducting clinical trials; the Company's inability
to obtain regulatory approval in a timely manner or at all; the Company's
history of operating losses and the potential for future losses, which may
lead the Company to not be able to continue as a going concern; the Company's
need for substantial additional financing to meet its business objectives; the
potential for the loss of funding from the Company's R&D grants and contracts
and its ability to win additional funding under such grants and contracts.
Some of these factors could cause future results to materially differ from the
recent results or those projected in forward-looking statements.See also the
"Risk Factors" and "Forward-Looking Statements" described in the Company's
periodic filings with the Securities and Exchange Commission.

CONTACT: Rachel Levine, Vice President, Investor Relations
         Cleveland BioLabs, Inc.
         T: (646) 284-9439
         Annie Deck-Miller, Senior Media Relations Manager
         Roswell Park Cancer Institute
         T: (716) 845-8593

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