Human Genome Sciences Announces Initiation of Phase 2b Trial of Albuferon(R) Dosed...

Human Genome Sciences Announces Initiation of Phase 2b Trial of Albuferon(R)
Dosed Monthly in Chronic Hepatitis C

- Trial conducted by Novartis to evaluate safety and efficacy of Albuferon
administered every four weeks in combination with ribavirin in patients with
genotypes 2 and 3 hepatitis C -

ROCKVILLE, Md., Jan. 12 /PRNewswire-FirstCall/ -- Human Genome Sciences, Inc.
(Nasdaq: HGSI) today announced that Novartis has initiated dosing in a Phase
2b trial that will evaluate the safety and efficacy of Albuferon(R)
(albinterferon alfa-2b) administered monthly in combination with ribavirin in
treatment-naive patients with genotypes 2 and 3 chronic hepatitis C.
Albuferon is being developed by HGS and Novartis under an exclusive worldwide
co-development and commercialization agreement entered into in June 2006.

(LOGO: http://www.newscom.com/cgi-bin/prnh/20080416/HGSLOGO )

"Patients undergoing treatment for chronic hepatitis C often find it
challenging to participate in normal daily activities, especially in the days
following dose administration," said Stephen Pianko, M.D., F.R.A.C.P., Ph.D.,
Monash University, Melbourne, Australia. "Pegylated interferons, the current
standard of care, require administration once every week. Albinterferon
alfa-2b dosed every four weeks with a total of six injections could offer an
important treatment option, if it demonstrates comparable safety and efficacy
vs. peginterferon alfa-2a dosed weekly with a total of 24 injections."

In December 2008, HGS announced that Albuferon met its primary endpoint of
non-inferiority to peginterferon alfa-2a (Pegasys) in ACHIEVE 2/3, a Phase 3
clinical trial of Albuferon in combination with ribavirin in treatment-naive
patients with genotypes 2 and 3 chronic hepatitis C. In these patients, the
Phase 3 study showed that 900-mcg Albuferon administered every two weeks had
efficacy comparable to peginterferon alfa-2a, with comparable rates of severe
and/or serious adverse events and discontinuations due to adverse events.

"Hepatitis C is the most common chronic blood-borne infection in the developed
world, and there continues to be a significant need for more effective and
better tolerated treatments," said Mani Subramanian, M.D., Ph.D., Executive
Director, Clinical Research - Infectious Diseases, HGS. "Only an estimated
40% of U.S. patients diagnosed with chronic hepatitis C have undertaken
treatment to date - in part due to the side effects associated with interferon
injections, which are currently required on a weekly basis. A monthly dosing
schedule with Albuferon may well result in more patients choosing to be
treated."

About the Design of the Phase 2b Monthly Dosing Trial

This Phase 2b trial is a randomized, open-label, multi-center,
active-controlled, adaptive-design dose-ranging study to evaluate the safety
and efficacy of albinterferon alfa-2b administered every four weeks plus daily
ribavirin in treatment-naive patients with genotypes 2 and 3 chronic hepatitis
C. Approximately 375 patients will be randomized in a 4:4:4:3 ratio into four
treatment groups, including three that will receive albinterferon alfa-2b
administered once every four weeks (900 mcg, 1200 mcg or 1500 mcg), in
addition to the active-control group, which will receive peginterferon alfa-2a
at the standard 180-mcg dose once every week. All patients in the study will
receive 800-mg daily oral ribavirin. The total duration of treatment will be
24 weeks. The primary efficacy endpoint is sustained virologic response (SVR)
at Week 48 (24 weeks following the end of treatment).

About Albinterferon Alfa-2b (Albuferon)

Albinterferon alfa-2b is a novel, longer-acting form of interferon alfa that
was created using the proprietary HGS albumin-fusion technology. Human
albumin is the most prevalent naturally occurring blood protein in the human
circulatory system, persisting in circulation in the body for approximately 19
days. Research has shown that genetic fusion of therapeutic proteins to human
albumin decreases clearance and prolongs the half-life of the therapeutic
proteins. Albuferon results from the genetic fusion of human albumin and
interferon alfa.

Albuferon is being developed by HGS and Novartis for the treatment of chronic
hepatitis C under an exclusive worldwide co-development and commercialization
agreement entered into in June 2006. HGS and Novartis will co-commercialize
Albuferon in the United States and will share clinical development costs, U.S.
commercialization costs and U.S. profits equally. Novartis will be responsible
for commercialization in the rest of the world and will pay HGS a royalty on
those sales. Clinical development, commercial milestone and other payments to
HGS could total as much as $507.5 million, including $132.5 million received
to date.

About Hepatitis C

Hepatitis C is an inflammation of the liver caused by the hepatitis C virus.
It is estimated that as many as 170 million people worldwide are infected with
hepatitis C virus. This includes nearly four million people in the United
States. When detectable levels of HCV persist in the blood for at least six
months, a person is diagnosed with chronic hepatitis C. Hepatitis C virus can
cause serious liver disease, leading to cirrhosis, primary liver cancer and
even death.

About Human Genome Sciences

The mission of HGS is to apply great science and great medicine to bring
innovative drugs to patients with unmet medical needs. The HGS clinical
development pipeline includes novel drugs to treat hepatitis C, lupus,
inhalation anthrax and cancer. The Company's primary focus is rapid progress
toward the commercialization of its two key lead drugs, Albuferon(R)
(albinterferon alfa-2b) for hepatitis C and LymphoStat-B(R) (belimumab) for
lupus. Phase 3 clinical trials of both drugs are ongoing. ABthrax(TM)
(raxibacumab) is in late-stage development for inhalation anthrax, and the
Company is awaiting authorization to begin delivery of ABthrax to the U.S.
Strategic National Stockpile. HGS also has three drugs in clinical development
for the treatment of cancer, including two TRAIL receptor antibodies and a
small-molecule antagonist of IAP (inhibitor of apoptosis) proteins. In
addition, HGS has substantial financial rights to certain products in the GSK
clinical pipeline including darapladib, which GSK has advanced to Phase 3
development as a potential treatment for coronary heart disease.

For more information about HGS, please visit the Company's web site at
www.hgsi.com. Health professionals and patients interested in clinical trials
of HGS products may inquire via e-mail to clinical_trials@hgsi.com or by
calling HGS at (301) 610-5790, extension 3550.

HGS, Human Genome Sciences, ABthrax, Albuferon and LymphoStat-B are trademarks
of Human Genome Sciences, Inc.

Safe Harbor Statement

This announcement contains forward-looking statements within the meaning of
Section 27A of the Securities Act of 1933, as amended, and Section 21E of the
Securities Exchange Act of 1934, as amended. The forward-looking statements
are based on Human Genome Sciences' current intent, belief and expectations.
These statements are not guarantees of future performance and are subject to
certain risks and uncertainties that are difficult to predict. Actual results
may differ materially from these forward-looking statements because of the
Company's unproven business model, its dependence on new technologies, the
uncertainty and timing of clinical trials, the Company's ability to develop
and commercialize products, its dependence on collaborators for services and
revenue, its substantial indebtedness and lease obligations, its changing
requirements and costs associated with facilities, intense competition, the
uncertainty of patent and intellectual property protection, the Company's
dependence on key management and key suppliers, the uncertainty of regulation
of products, the impact of future alliances or transactions and other risks
described in the Company's filings with the Securities and Exchange
Commission. In addition, the Company will continue to face risks related to
animal and human testing, to the manufacture of ABthrax and to FDA concurrence
that ABthrax meets the requirements of the ABthrax contract. If the Company is
unable to meet the product requirements associated with the ABthrax contract,
the U.S. government will not be required to reimburse the Company for the
costs incurred or to purchase any ABthrax doses. Existing and prospective
investors are cautioned not to place undue reliance on these forward-looking
statements, which speak only as of today's date. Human Genome Sciences
undertakes no obligation to update or revise the information contained in this
announcement whether as a result of new information, future events or
circumstances or otherwise.

SOURCE Human Genome Sciences, Inc.

Media: Jerry Parrott, Vice President, Corporate Communications,
+1-301-315-2777; or Investors: Tim Barabe, Senior Vice President and Chief
Financial Officer, +1-301-315-1780, both of Human Genome Sciences, Inc.