New Data Shows Breakthrough microRNA-Targeted Therapy Developed Using Santaris Pharma A/S Proprietary LNA Technology Holds Promise as New Treatment for Hepatitis C

SPC3649 Successfully Inhibits miR-122, a microRNA Important for Hepatitis C Viral Replication, Thereby Significantly Reducing Hepatitis C Virus in the Bloodstream in Chimpanzees Chronically Infected With the Hepatitis C Virus

HOERSHOLM, Denmark and SAN DIEGO, California, December 3 - A study published online in this week's Science shows that
SPC3649, a breakthrough microRNA-targeted therapy developed by Santaris
Pharma A/S using its proprietary Locked Nucleic Acid (LNA) technology, holds
promise as a novel treatment for patients infected with the Hepatitis C virus
(HCV).

(Logo: www.newscom.com/cgi-bin/prnh/20090921/360545 )

The World Health Organization estimates about 3% of the
world's population has been infected with HCV and that some 170 million are
chronic carriers at risk of developing liver cirrhosis and/or liver
cancer[1]. Approximately 3-4 million Americans are chronically infected with
an estimated 40,000 new infections per year[2]. In Europe, there are about 4
million carriers[3].

Santaris Pharma A/S, the first company to have advanced both
mRNA and microRNA targeted drugs into clinical trials, is an international
biopharmaceutical company focused on the discovery and development of
RNA-targeted therapies for a range of diseases including metabolic disorders,
infectious and inflammatory diseases, cancer and rare genetic disorders.

In this preclinical study, SPC3649 successfully inhibited
miR-122, a liver-expressed microRNA important for Hepatitis C viral
replication. By inhibiting miR-122, SPC3649 dramatically reduced Hepatitis C
virus in the liver and in the bloodstream in chimpanzees chronically infected
with the Hepatitis C virus[4]. Four HCV chronically infected chimpanzees were
treated weekly with 5 or 1 mg/kg of SPC3649 for 12 weeks followed by a
treatment free period of 17 weeks. The two animals that received the 5 mg/kg
dose had a significant decline in viral levels in the blood and liver of
approximately 2.5 orders of magnitude or approximately 350 fold[5].

"In collaborating with Santaris Pharma, we proved that the
drug worked exceptionally well in treating HCV infections in chimpanzees,"
said Robert Lanford, Ph.D., a scientist at the Southwest Foundation for
Biomedical Research and one of the lead authors on the study. "The current
standard anti-HCV treatment, which combines pegylated interferon-alpha with
ribavirin, is effective in only about 50% of patients and is often associated
with severe side effects. Because of the unique mechanism of action of
SPC3649 and its tolerability profile, this new therapy could have the
potential to replace interferon to treat disease progression or be combined
with current treatments."

SPC3649 provided continued efficacy in the animals up to
several months after the treatment period with no adverse events and no
evidence of viral rebound or resistance, an important factor that
distinguishes SPC3649 from direct antiviral HCV therapeutics.

Current antiviral therapies that target the virus directly are
challenged as the HCV continually mutates to develop resistance to treatment.
Because SPC3649 inhibits miR-122, an important microRNA involved in HCV
replication, the HCV is blocked from replicating without the apparent
selection of resistant mutants. SPC3649 has other important properties that
make it attractive as a therapeutic agent for HCV. The preclinical data show
changes in the expression of key genes that may help patients who do not
respond to interferon treatment to become responsive.

SPC3649 is the first microRNA-targeted drug to enter human clinical
trials and is currently undergoing Phase 1 clinical studies in healthy
volunteers. These preclinical data provide even greater impetus to further
examine the potential of SPC3649 for treating patients infected with HCV.

"Advancing the first microRNA-targeted therapy, SPC3649, into
human clinical trials was certainly a breakthrough in science and we are very
encouraged by these preclinical findings demonstrating that SPC3649 has the
potential to be an effective treatment for patients infected with the
Hepatitis C virus," said Henrik 0rum, Ph.D., Vice President and Chief
Scientific Officer of Santaris Pharma A/S. "In drug discovery and development
programs internally and with our partners, we continue to demonstrate that
our proprietary LNA Drug Platform is fundamental in developing effective
RNA-targeted therapies with high affinity, target specificity and remarkable
potency for a range of diseases."

Santaris Pharma A/S has a robust product pipeline based on its
proprietary LNA technology including mRNA and microRNA drug discovery and
development partnerships and collaborations with Shire (rare genetic
disorders), Wyeth, now part of Pfizer, (delivery of lead candidates against
up to ten targets), GlaxoSmithKline (four viral disease drug candidates) and
Enzon Pharmaceuticals (eight cancer targets successfully delivered).

About Locked Nucleic Acid (LNA) Drug Platform

The Locked Nucleic Acid (LNA) Drug Platform developed by
Santaris Pharma A/S creates synthetically modified chemical versions of the
normal nucleic acid building blocks of ribonucleic acids (RNA). These
modified chemical versions called LNAs improve the drug-like qualities of
resulting therapeutics (oligonucleotides) by improving affinity to their
target RNA, boosting resistance to metabolism and improving tissue uptake.
Upon systemic administration of these "naked" molecules, LNA-based
therapeutics are delivered to many different tissues where they show
potencies many-fold better than other oligonucleotide therapeutics.

About Santaris Pharma A/S

Santaris Pharma A/S is a clinical-stage biopharmaceutical
company focused on the discovery and development of RNA-targeted therapies.
The Company's proprietary Locked Nucleic Acid (LNA) Drug Platform, in
combination with its highly specialized and targeted drug development
capabilities, offers potential partners pre-screened drug candidates for
commercial consideration across a multitude of disease states. Santaris
Pharma A/S research and development activities focus on infectious diseases
and metabolic disorders while partnerships with major pharmaceutical
companies include a range of therapeutic areas including cancer, rare genetic
disorders and inflammatory diseases. Santaris Pharma A/S, founded in 2003, is
privately-held and headquartered in Denmark with operations in the US. As
part of its broad patent estate, the Company holds exclusive worldwide rights
to all therapeutic uses of LNAs. The Company has strategic partnerships with
Enzon Pharmaceuticals, GlaxoSmithKline, Wyeth Pharmaceuticals (now part of
Pfizer) and Shire plc. Please visit www.santaris.com for more
information.

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[1] World Health Organization -
www.who.int/csr/disease/hepatitis/Hepc.pdf

[2] American Association for the Study of Liver Diseases -
www.aasld.org/patients/Pages/LiverFastFactsHepC.aspx

[3] World Health Organization -
www.who.int/csr/disease/hepatitis/Hepc.pdf

[4] The chimpanzee is the only animal other than humans that is
susceptible to HCV

[5] Lanford et al, Therapeutic silencing of microRNA-122 in primates with
chronic hepatitis C virus infection, Science online

    Media Contact:

    Navjot Rai
    Santaris Pharma A/S
    Office: +1-858-764-7064 ext. 206
    Cell: +1-619-723-5450
    e-mail: navjot.rai@santaris.com

Navjot Rai, Santaris Pharma A/S, Office: +1-858-764-7064 ext. 206, Cell: +1-619-723-5450, e-mail: navjot.rai at santaris.com