XTL
Biopharmaceuticals Ltd. (Nasdaq: XTLB, TASE: XTL) announced that it
will make two scientific presentations related to its pre-clinical
Hepatitis C virus (HCV) small molecule program at HEP DART 2007, an
international scientific conference on viral hepatitis being held this week
in Lahaina, Hawaii.
A poster presentation entitled "Mechanistic Characterization of Potent
Small Molecule HCV Inhibitors that Target NS5A" describes a family of small
molecule inhibitors of HCV that target the NS5A viral protein. Potency of
these compounds was evaluated in a replicon assay, which is known to have
good correlation with clinical efficacy and is the current gold standard
for pre- clinical testing of inhibitors of HCV. In the replicon assay, the
compounds had single-digit nM (nanomolar) and low double-digit nM potencies
against genotypes 1b and 1a, respectively. These genotypes constitute the
majority of HCV infections in the U.S.
New data presented further substantiate NS5A as the target of these
compounds. The new data includes results from in vitro binding to NS5A,
resistance selection, molecular genetic and molecular modeling studies.
NS5A is a viral protein that is essential for RNA production and is
distinct from the protease and polymerase - the viral targets of the more
advanced HCV inhibitors in clinical development. As such, inhibitors of
NS5A are considered promising candidates for the treatment of HCV. As a
relatively new target, only one NS5A inhibitor has entered clinical trials
to date - A831 - which is presently in a Phase 1 clinical trial. A831 was
developed by Arrow Therapeutics, which was recently acquired by
AstraZeneca. The Company's compounds presented appear to be significantly
more potent than A831 in the replicon assay.
A second poster presentation entitled "Pharmacologic Evaluation of
Novel Small Molecule HCV Inhibitors Affecting NS5A-dependent Functions"
describes the results of studies on the potency, specificity, toxicology
and pharmacokinetics of the Company's lead HCV molecules. In these studies,
when administered orally to rodents, the compounds demonstrated
preferential accumulation in the liver in concentrations that were orders
of magnitude above those required to block viral replication as predicted
by the replicon assay, with half-lives consistent with a twice a day dosing
regimen. Toxicology studies showed that the activity of these molecules was
selective for HCV, with no apparent adverse effects on a range of human
cell types or on rodents exposed to repeated high doses.
The small molecules being presented by the Company at the conference
emerged from the Company's DOS program, aimed at discovering novel HCV
inhibitors by applying a unique chemistry technology called Diversity
Oriented Synthesis.
ABOUT HEPATITIS C VIRUS
There are approximately 3 million people infected with HCV in the U.S.
alone. HCV infection significantly increases the infected person's risk of
developing chronic liver disease, cirrhosis and liver cancer, and is the
leading cause of liver transplantation in the Western World. HCV infection
remains a major unmet medical need as the current standard of care
(interferon-based therapy) achieves success in only 50% of patients
infected with genotype 1 of the virus (genotype 1 affects 75% patients in
the U.S.), and has significant side affects associated with it.
ABOUT XTL BIOPHARMACEUTICALS LTD.
XTL Biopharmaceuticals Ltd. ("XTL") is engaged in the development of
therapeutics for the treatment of neuropathic pain and HCV. XTL is
developing Bicifadine, a serotonin and norepinephrine reuptake inhibitor,
for the treatment of diabetic neuropathic pain, which is currently in a
Phase 2b study. XTL is also developing novel pre-clinical HCV small
molecule inhibitors. XTL also has an active in-licensing and acquisition
program designed to identify and acquire additional drug candidates. XTL is
publicly traded on the NASDAQ and Tel-Aviv Stock Exchanges (Nasdaq: XTLB;
TASE: XTL).
Cautionary Statement
Some of the statements included in this press release, particularly
those anticipating future performance and prospects of our pre-clinical
compounds for HCV from our XTL-DOS program, may be forward-looking
statements that involve a number of risks and uncertainties. For those
statements, we claim the protection of the safe harbor for forward-looking
statements contained in the Private Securities Litigation Reform Act of
1995. Among the factors that could cause our actual results to differ
materially are the following: our ability to successfully complete the
pre-clinical development DOS program; our ability to clinically develop
candidates from the DOS program; and other risk factors identified from
time to time in our reports filed with the Securities and Exchange
Commission, including our annual report on Form 20-F filed with the
Securities and Exchange Commission on March 23, 2007. Any forward-looking
statements set forth in this press release speak only as of the date of
this press release. We do not intend to update any of these forward-looking
statements to reflect events or circumstances that occur after the date
hereof. This press release and prior releases are available at
xtlbio. The information in our website is not incorporated
by reference into this press release and is included as an inactive textual
reference only.
XTL Biopharmaceuticals Ltd.
xtlbio