Archemix Initiates Phase 2a for Lead Aptamer Product Candidate ARC1779

Company Achieves Key Clinical Milestone with Initiation of Second Phase 2 Trial
for ARC1779
CAMBRIDGE, Mass.--(Business Wire)--
Archemix Corp., a privately-held biotechnology company working to develop
aptamer-based therapeutics, announced today that it has initiated a Phase 2a
clinical trial of its novel anti-von Willebrand Factor (VWF) aptamer, ARC1779.
The trial is designed to evaluate the safety and efficacy of ARC1779 as a
potential first-in-class anti-platelet agent in patients with carotid artery
disease undergoing a surgical procedure known as carotid endarterectomy, or CEA.

The recently initiated Phase 2a trial is a randomized, double-blind,
placebo-controlled study to evaluate the efficacy, safety and tolerability of
ARC1779 in approximately 100 CEA patients at multiple centers in North America
and Europe. The primary objectives of the trial will be to measure the
effectiveness of ARC1779 in reducing the number of small blood clots which form
immediately following the operation and then flow to the brain, and to assess
the bleeding risk of ARC1779 in this setting. Secondary objectives include
evaluating the effect of ARC1779 administration on reducing the brain injury
caused by the small blood clots formed immediately following the operation. The
study will also assess the pharmacokinetic and pharmacodynamic profile of
ARC1779.

"Current anti-platelet agents such as aspirin, even when used in combination
with one another, fail to adequately protect patients from recurrent strokes.
There is an unmet medical need for anti-platelet agents that can improve the
success rate for stroke prevention," commented Dr. Hugh Markus Professor of
Neurology and Clinical Neuroscience at St. George's, University of London, the
lead investigator in the Phase 2a trial. "Because of the unique biology of VWF,
we believe that ARC1779 can locally inhibit clot formation and reduce stroke
risk, while reducing the bleeding complications that are associated with
existing anti-platelet agents."

About CEA

Carotid endarterectomy is a surgical procedure which removes an unwanted
build-up of inflammatory cells, cholesterol and cellular debris known as plaque
from the inner lining of the major arteries in the neck which supply blood to
the brain. These vessels, known as the carotid arteries, can become narrowed by
plaque, causing a reduction in blood flow to the brain. Blood clots can form on
the surface of the plaque. Plaque or clots can then break loose and travel to
the brain, blocking the blood flow to the brain and potentially causing
permanent brain damage, stroke or death, if a large enough area of the brain is
affected. If a clot or plaque blocks only a tiny artery in the brain, it may
cause a transient ischemic attack, or TIA, also known as a ministroke. For
patients experiencing a minor stroke or a TIA, a surgeon may recommend the
surgical procedure known as carotid endarterectomy to remove plaque in the
carotid arteries and help prevent a stroke. According to the Agency for
Healthcare Research and Quality, more than 114,000 carotid endarterectomy
procedures were performed in the United States in 2006.

About ARC1779

Archemix`s lead aptamer product candidate, ARC1779, is a PEGylated aptamer
consisting of 40 nucleotides. ARC1779 is designed to inhibit the function of a
protein called von Willebrand Factor, or VWF, which, when activated, is
responsible for the adhesion, activation and aggregation of platelets by a
mechanism distinct from those targeted by marketed anti-platelet therapies such
as aspirin, clopidogrel and Gp IIb/IIIa inhibitors. In addition to the Phase 2a
clinical trial in patients with CEA, Archemix is also conducting a Phase 2b
clinical trial with ARC1779 in patients suffering from a group of rare,
life-threatening blood disorders known as thrombotic microangiopathies, or TMA,
a condition for which there is currently no specifically approved drug
treatment. ARC1779 has received orphan designation for the treatment of TTP in
both the United States and the European Union.

About Aptamers

Aptamers are synthetically-derived oligonucleotides, or short nucleic acid
sequences, that bind to protein targets with high affinity and specificity and
can be designed to have a specified duration of action. Aptamers represent an
emerging class of potential therapeutic agents that Archemix believes may have
broad application to treat a variety of human diseases.

About Archemix

Archemix is a biotechnology company focused on discovering, developing and
commercializing aptamer therapeutics. Using Archemix`s processes for discovering
aptamers, which are protected by its broad patent portfolio, Archemix is
developing aptamer product candidates for rare hematological diseases. In
addition, Archemix has licensed its intellectual property to third parties to
develop their own aptamer product candidates in other areas. Currently,
Archemix`s licensees are evaluating five different aptamer product candidates in
human clinical trials; two in Phase 2 and three in Phase 1. Archemix has
additional partnerships with several pharmaceutical and biotechnology companies,
including GlaxoSmithKline, Merck Serono, Pfizer, Takeda, Eli Lilly and Isis
Pharmaceuticals.

Media:
For Archemix
Kathryn Morris, 845-635-9828
Cell: 914-204-6412

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