BioCryst's Partner Shionogi Files for Peramivir Regulatory Approval in Japan

BIRMINGHAM, Ala., Nov. 4 /PRNewswire-FirstCall/ -- BioCryst Pharmaceuticals,
Inc. (Nasdaq: BCRX) today announced that its partner, Shionogi & Co., Ltd. has
filed a New Drug Application (NDA) in Japan to seek regulatory approval for
intravenous (i.v.) peramivir to treat patients with influenza. As a
consequence of this filing, BioCryst will receive a regulatory milestone
payment of $7 million under its agreement with Shionogi.

"We congratulate Shionogi on this accomplishment and the great effort its team
made to swiftly prepare the filing. This is the first application for
marketing approval of peramivir in any country and it is a significant
landmark for BioCryst," said Jon P. Stonehouse, President and Chief Executive
Officer of BioCryst. "BioCryst continues to work with U.S. agencies, other
governments and our partners to provide i.v. peramivir as a treatment option
for hospitalized patients with influenza during the ongoing pandemic, and to
complete the development of peramivir through the traditional regulatory
pathway."

About peramivir

Peramivir is a potent, intravenously administered anti-viral agent that
rapidly delivers high plasma concentrations to the sites of infection.
Discovered by BioCryst, peramivir inhibits the interactions of influenza
neuraminidase, an enzyme which is critical to the spread of influenza within a
host. In laboratory tests, peramivir has shown activity against pandemic H1N1
swine flu origin viral strains. Peramivir has been studied in patients with
complicated and uncomplicated influenza. On October 23, 2009, BioCryst
announced that the U.S. Food and Drug Administration (FDA) issued an emergency
use authorization (EUA) for i.v. peramivir in certain adult and pediatric
patients with confirmed or suspected 2009 H1N1 influenza infection who are
admitted to a hospital. Additional information regarding the peramivir EUA is
available on the web at: http://www.cdc.gov/h1n1flu/eua/.

About Influenza

According to the CDC, on average in the U.S., approximately 200,000 people are
hospitalized from flu complications and 36,000 people die from flu-related
causes each year. Influenza (the flu) is a contagious respiratory illness
caused by influenza viruses.

More information is available at:
http://www.cdc.gov/flu/
http://www.hhs.gov/pandemicflu/plan/pdf/HHSPandemicInfluenzaPlan.pdf

About the Shionogi & Co., Ltd. Partnership

In February 2007, BioCryst and Shionogi & Co., Ltd. entered into an exclusive
license agreement under which Shionogi obtained rights to develop and
commercialize peramivir in Japan for the treatment of seasonal and potentially
life-threatening influenza. In 2008, Shionogi's rights were extended to
include Taiwan. Under the terms of the agreement, BioCryst may receive future
regulatory and commercial event milestone payments up to $102 million, as well
as double digit royalty payments on product sales of peramivir. BioCryst
retains its rights to commercialize peramivir in countries outside of Japan,
Taiwan and South Korea.

About BioCryst

BioCryst Pharmaceuticals designs, optimizes and develops novel small-molecule
pharmaceuticals that block key enzymes involved in infectious diseases, cancer
and inflammatory diseases. BioCryst has progressed two novel compounds into
late-stage pivotal clinical trials; peramivir, an anti-viral for influenza,
and forodesine, a purine nucleoside phosphorylase (PNP) inhibitor for
cutaneous T-cell lymphoma (CTCL). Utilizing crystallography and
structure-based drug design, BioCryst continues to discover additional
compounds and to progress others through pre-clinical and early development to
address the unmet medical needs of patients and physicians. The Company's
strategic alliances with the U.S. Department of Health and Human Services,
Shionogi & Co., Ltd., Green Cross Corporation and Mundipharma International
Holdings Limited validate its scientific foundation and the utility of its
product candidates. For more information, please visit the Company's Web site
at www.biocryst.com.

Forward-Looking Statements

This press release contains forward-looking statements, including statements
regarding future results, performance or achievements. These statements
involve known and unknown risks, uncertainties and other factors which may
cause our actual results, performance or achievements to be materially
different from any future results, performances or achievements expressed or
implied by the forward-looking statements. These statements reflect our
current views with respect to future events and are based on assumptions and
subject to risks and uncertainties. Given these uncertainties, you should not
place undue reliance on these forward-looking statements. Some of the factors
that could affect the forward-looking statements contained herein include:
that the U.S. government and ex-U.S. governments may choose not to issue a
request for peramivir to treat influenza or such requests, if any, may not
result in an order or such order, if any, may not be profitable for BioCryst;
that to the extent peramivir is used as a treatment for H1N1 flu (or other
strains of flu), there can be no assurance that it will prove effective; that
HHS may further condition, reduce or eliminate future funding of the peramivir
program; that ongoing peramivir clinical trials or our peramivir program in
general may not be successful; that BioCryst or its licensees may not commence
as expected additional human clinical trials with our product candidates; that
our product candidates may not receive required regulatory clearances from the
FDA; that ongoing and future pre-clinical and clinical development may not
have positive results; that we or our licensees may not be able to continue
future development of our current and future development programs; that our
development programs and partnerships may never result in future product,
license or royalty payments being received by BioCryst; that BioCryst may not
be able to retain its current pharmaceutical and biotechnology partners for
further development of its product candidates or it may not reach favorable
agreements with potential pharmaceutical and biotechnology partners for
further development of its product candidates; that our actual cash burn rate
may not be consistent with our expectations; that BioCryst may not have
sufficient cash to continue funding the development, manufacturing, marketing
or distribution of its products and that additional funding, if necessary, may
not be available at all or on terms acceptable to BioCryst. Please refer to
the documents BioCryst files periodically with the Securities and Exchange
Commission, specifically BioCryst's most recent Annual Report on Form 10-K,
most recent Registration Statement on Form S-3 (filed November 28, 2008),
Quarterly Reports on Form 10-Q, and current reports on Form 8-K, all of which
identify important factors that could cause the actual results to differ
materially from those contained in our projections and forward-looking
statements.

BCRXW

SOURCE BioCryst Pharmaceuticals, Inc.

Robert Bennett, BioCryst Pharmaceuticals, +1-919-859-7910