http://news.excite.com/news/pr/011112/nj-pharmos-corp-neuro
Mon, Nov 12 9:39 AM EST
ISELIN, N.J., Nov. 12 /PRNewswire/
-- Pharmos Corporation (Nasdaq: PARS and Nasdaq Europe: PHRM) is presenting
this week at the Society for Neuroscience Annual Meeting in San Diego three
papers demonstrating the potential activity of its non-psychotropic dextrocannabinoids
as agents to treat neuro-inflammatory disorders. Two of the papers present
positive preclinical results in animal models for stroke and Parkinson's
Disease. For stroke, PRS-211,095 was shown to induce significant dose-dependent
functional recovery as well as reduction in brain infarct size following
transient middle cerebral artery occlusion (MCAo) in rats. In a Parkinson's
Disease mouse model, dexanabinol protected dopaminergic neurons of the
central nervous system from MPTP toxicity.
"The positive results we are obtaining
with our compounds in animal models for various neurological indications
support our decision to invest greater resources in this area of development.
The sale of our ophthalmic business to Bausch & Lomb last month will
help us advance promising early-stage programs into development and thereby
strengthen our neurological pipeline," said Dr. George Fink, Vice President
of Research at Pharmos.
The third paper extends scientific
understanding of the mechanisms of action of Pharmos' dextrocannabinoids.
Collaborative studies with Drs. Marcus Schwaninger and Eric Juettler (Department
of Neurology, University of Heidelberg) show for the first time that dexanabinol
inhibits NF-kappaB, an important transcription factor in neuroinflammatory
processes. Fink explained, "These results and data to be announced in the
future demonstrate that our dextrocannabinoids affect cell signaling, particularly
via gene regulation, cytokines and chemokines, and strengthen our ability
to optimize our lead compounds and identify new clinical indications."
Stroke Study
Stroke was induced in rats by a 120-minute
occlusion of the MCA, a standard animal model for focal ischemia. The animals
were treated with a single intravenous injection of 0.5, 2.5, 5 or 10 mg/kg
PRS-211,095 or vehicle alone at the end of MCAo. The neuroprotective efficacy
of the compound was evaluated by brain infarct volume and by neurological
outcome tested in the "staircase test," which measures a combination of
sensory and motor skills similar to those impaired in humans who suffer
a stroke. A dose-related improvement in performance in the staircase test
was seen with PRS-211,095 (40-80% compared with vehicle alone, p is less
than 0.05 at 0.5, 5 and 10 mg/kg). Infarct volume was reduced with all
doses of PRS-211,095, with the 5 mg/kg dose showing a 44% reduction compared
with vehicle alone.
Parkinson's Disease Study
MPTP is a toxin that induces a severe
and irreversible Parkinson's Disease-like syndrome. In mice the agent causes
a massive loss of the tyrosine hydroxylase (TH) immunoreactive (dopaminergic)
cells in the substantia nigra, a key motor-control center of the brain
that undergoes degeneration in Parkinson's Disease. Mice were injected
with either MPTP toxin or saline four times at two-hour intervals. The
MPTP-injected mice were treated with either dexanabinol (10, 20, 30 mg/kg)
or its vehicle just before the first MPTP injection. One group of MPTP-injected
mice was left untreated. After seven days, brain sections were analyzed
for TH-positive cells by immunohistochemistry. Brain sections from mice
treated with 20 mg/kg dexanabinol had 25-30% more TH-positive cells in
the substantia nigra than sections from mice treated with vehicle alone
(p is less than 0.05).
Dexanabinol Inhibition of NF-kappaB
Dexanabinol exerts anti-inflammatory
effects, including the ability to inhibit expression of tumor necrosis
factor (TNF) alpha. The gene expression of TNFalpha and various other mediators
of inflammation are regulated by NF-kappaB, an essential transcription
factor for many genes involved in the pathophysiology of brain damage,
including cerebral ischemia and neural cell death. To investigate the effect
of dexanabinol on NF-kappaB activation, U373 MG cells, an astrocytoma cell
line, were transiently transfected with a reporter fusion gene that is
under transcriptional control of NF-kappaB. Stimulation of NF-kappaB activity
by TNFalpha, detected by luciferase assay, was inhibited by dexanabinol
in a concentration-dependent manner. Western blot and gelshift assays were
also employed and indicated dexanabinol inhibited NF-kappaB activation
and nuclear translocation by its ability to block the TNFalpha-induced
degradation of the NF-kappaB inhibitor, IkappaBalpha. In summary, the results
show that dexanabinol is capable of inhibiting the activation of NF-kappaB,
a mechanism by which dexanabinol could protect neuronal and other cells
during neuroinflammation or ischemia.
Synthetic Non-Psychotropic Dextrocannabinoid
Library
Pharmos is conducting both clinical
and preclinical studies with neuroprotective compounds from its library
of proprietary, synthetic, non-psychotropic dextrocannabinoids. The most
advanced compound, dexanabinol, is in a pivotal Phase III clinical trial
to treat traumatic brain injury (TBI). Another compound from the company's
technology platform is in last-stage preclinical development for stroke.
Beyond TBI and stroke, Pharmos believes its technology holds great promise
in the development of safe and effective treatments for neuropathic pain,
multiple sclerosis (MS) and other neurological and autoimmune conditions
in which neuroinflammation is central to the pathology.
Pharmos Corporation discovers and
develops novel therapeutics to treat a range of neurological disorders,
in particular those in which inflammation plays a role, such as traumatic
brain injury and stroke. The Company has an extensive portfolio of drug
candidates under development, as well as discovery, preclinical and clinical
capabilities.
Statements made in this press release
related to operational expectations and projections of the Company are
forward-looking and are made pursuant to the safe harbor provisions of
the Securities Litigation Reform Act of 1995. Such statements involve risks
and uncertainties which may cause results to differ materially from those
set forth in these statements. Additional economic, competitive, governmental,
technological, marketing and other factors identified in Pharmos' filings
with the Securities and Exchange Commission could affect such results.
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