Nanotechnology Now - Press Release: Arrowhead announces issuance of patent on subsidiary's key technology

Home > Press > Arrowhead announces issuance of patent on subsidiary's key technology

Abstract:
Arrowhead Research Corporation (Nasdaq:
ARWR), announced today that European Patent No. 1093469, titled
"Linear Cyclodextrin Copolymers" has been issued to the California
Institute of Technology. The patent is exclusively licensed to
Arrowhead's majority-owned subsidiary, Insert Therapeutics, a company
commercializing delivery-enhanced therapeutics using a patented class
of polymeric systems.

Arrowhead announces issuance of patent on subsidiary's key technology

Pasadena, CA | Posted on May 8th, 2007

"Having strong patent protection is crucial to high tech companies,
particularly those in the nanotech space," said R. Bruce Stewart,
Arrowhead's Chairman. "Arrowhead will continue to aggressively build
and protect our intellectual property rights."

This patent covers all of the claims in three previously issued US
patents covering the composition, method of preparation and methods
of use of a new class of polymers for delivery of therapeutic
compounds. Insert Therapeutics' proprietary Cyclosert technology
platform is a part of the family of polymers covered by these
patents, and represent a significant advance in the use of
cyclodextrins for delivery of therapeutic compounds.

Insert is currently using Cyclosert(TM) technology in its lead drug
candidate, IT-101, an experimental drug being studied for the
treatment of cancer in Phase I clinical trials at City of Hope Cancer
Center in Duarte, CA. Insert expect to commence multiple Phase II
trials later this year. IT-101 is a conjugate of one of the
Cyclosert(TM) polymers and the anti-cancer, small molecule drug
camptothecin.

Insert has also licensed a portion of the polymer family to its
affiliate, Calando Pharmaceuticals, which is using polymers to
deliver siRNA duplexes in the area of RNA interference, a novel
gene-silencing technology that may lead to an entire new class of
therapeutics. Calando is preparing to file with the FDA to begin
clinical trials later this year.

The claims cover polymers containing repeating units of cyclodextrin
molecules and various co-monomers, linked together in a linear chain.
In contrast to other approaches that graft molecules onto a polymer,
the claimed polymers incorporate the cyclodextrin molecules into the
polymer "backbone." This feature has aided in scale-up and resulted
in more consistent commercial manufacture. Insert's linear
cyclodextrin-containing polymers can form complexes with compounds
ranging in size from small molecule drugs to nucleic acids for
improved therapeutic effects.

Other issued and allowed patents cover various means of adding
modifier components to the polymer that aid the stability of the
resulting polymer-drug nanoparticles in vivo and allow for the
attachment of various targeting ligands.

For more information about Insert & Calando, please visit the
websites at http://www.insertt.com and http://www.calandopharma.com .

####

About Arrowhead Research Corporation
Arrowhead Research Corporation (www.arrowheadresearch.com) is a
publicly-traded nanotechnology company commercializing new
technologies in the areas of life sciences, electronics, and energy.
Arrowhead is building value for shareholders through the progress of
majority owned subsidiaries founded on nanotechnologies originally
developed at universities. The company works closely with
universities to source early stage deals and to generate rights to
intellectual property covering promising new nanotechnologies.
Currently, Arrowhead has four subsidiaries commercializing nanotech
products and applications, including anti-cancer drugs, RNAi
therapeutics, carbon-based electronics and compound semiconductor
materials.

About Insert Therapeutics Inc.

Insert Therapeutics, Inc. (www.insertt.com) is using its proprietary,
nano-engineered, polymeric delivery system, Cyclosert(TM), to design,
develop and commercialize drug-delivery-enhanced small-molecule
therapeutics and nucleic acids. Cyclosert uses cyclodextrins as
building blocks to create an entirely new class of biocompatible
materials - linear cyclodextrin-containing polymers that are
non-toxic and non-immunogenic at therapeutic doses. The company is
pursuing this goal through its internal research and development, and
also through collaborations and partnerships with pharmaceutical and
biotechnology companies.

About Calando Pharmaceuticals Inc.

Calando Pharmaceuticals Inc. (www.calandopharma.com ) is using its
proprietary technologies in targeted polymeric delivery systems and
siRNA design to design and create new, targeted siRNA therapeutics.
Small interfering RNAs (siRNA) use RNA interference, or RNAi, a
naturally occurring mechanism within cells to selectively silence and
regulate specific genes. The ability to silence genes selectively
through RNAi could provide a new way to treat a wide range of human
diseases. The company is pursuing this goal through its internal
research and development and also through collaborations and
partnerships with pharmaceutical and biotechnology companies.

Safe Harbor Statement under the Private Securities Litigation Reform
Act of 1995

This news release contains forward-looking statements within the
meaning ofthe "safe harbor" provisions of the Private Securities
Litigation Reform Actof 1995. These statements are based upon our
current expectations and speak onlyas of the date hereof. Our actual
results may differ materially and adversely from those expressed in
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uncertainties, including the recent economic slowdown affecting
technology companies, the future success of our scientific studies,
our ability to successfully develop products, rapid technological
change in our markets, changes in demand for our future products,
legislative, regulatory and competitive developments and general
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recent and forthcoming Quarterly Reports on Form 10-Q and 10-Q/A,
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