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October 22, 2003
Benitec Ltd (ASX: BLT)
announced today that it has successfully achieved the
simultaneous disabling of multiple genes through RNA
interference. The breakthrough is a result of Benitec’s
continuing research and development efforts in ddRNAi technology
to extend the Company’s patent portfolio in RNA interference
“The
breakthrough is significant for its potential to develop
powerful human therapeutics in an expanded range of diseases,”
said Benitec’s Chief Executive Officer, John McKinley. “We
believe our ‘multiple warhead’ capability will allow us to
understand more clearly those conditions that result from
multiple gene defects – conditions such as Type II diabetes,
autoimmune disorders, cardiovascular dysfunctions – and perhaps
also provide viable treatment regimes.”
“Today,
some of the world’s most serious diseases are demonstrating
resistance to existing drugs, as is the case with the increasing
problem of antibiotic-resistant bacteria. Most cancers and HIV,
in particular, have high mutation rates that increase the
probability of resistant variants.”
“A
promising approach to this issue,” he continued, “is to
simultaneously disable multiple targets. The greater number of
genes that can be targeted, the lower the possibility that any
one cell or virus would develop resistance to the treatment.”
The concept
of combination therapy, where several drugs attack multiple
targets simultaneously, is widely used in the treatment of
cancers. Benitec’s new multi-hit ddRNAi technology potentially
provides a single agent that could deliver potent and specific
‘drugs’ effectively against multiple targets. This approach of
combining targets in one therapeutic is preferable to attempting
to achieve the same results from multiple drugs as it eliminates
the possibility of any cell developing resistance by inadvertent
exposure to just one of the drugs.
About
ddRNAi
DNA
directed RNAi (ddRNAi) is a method to trigger the natural gene
suppression process called RNA interference (RNAi) that operates
by destroying messenger RNA (mRNA), the courier that delivers
instructions to the ribosomes within the cell to manufacture the
proteins coded for by DNA. By introducing a DNA construct into a
cell, Benitec’s ddRNAi technology triggers the production of
double-stranded RNA (dsRNA), which is then cleaved into small
interfering RNA (siRNA) as part of the RNAi process, resulting
in the destruction of the target mRNA and knocking-down or
silencing the expression of the target gene.
Benitec’s
ddRNAi provides the ability to control the silencing effect so
that it either knocks down or completely silences the target
gene. Control can also be exerted to make the silencing effect
transient or permanent. siRNA technologies under development are
only capable of transient silencing and are dose dependent,
unlike ddRNAi which is catalytic in its effect.
ddRNAi can
also be used with a range of efficient delivery options not
available to the siRNA approach, providing additional
versatility for therapeutics development. These qualities, among
others, make ddRNAi well suited to high throughput functional
genomics and target validation, and provide added versatility
when developing RNAi therapeutics.
About
Benitec Limited
Benitec Limited, based in Queensland, Australia, has key
Intellectual Property in the field of gene silencing using DNA
constructs to trigger RNA interference (granted patents include
US 6,573,099; GB 2353282; AU 2001100608). The Company was the
first to demonstrate RNA interference, a universal gene
silencing mechanism, in mammalian and human cells. This natural
mechanism is now recognized worldwide as the simplest and most
precise method for shutting down the activity of any specific
gene. The technology is immediately applicable to functional
genomics and the identification and validation of drug targets.
Benitec's technology can also be applied to the treatment of
major human diseases such as cancers, autoimmune disorders and
viral infections through the shutting down of disease-causative
genes. Other applications include plant improvement and the
breeding of viral resistant livestock. Benitec offers customers
licences to undertake research and development on its expanding
technology platform and tools to deliver the technology's full
capability. |