ViroPharma and Halozyme Therapeutics Announce Initiation of Phase 2b Dose Ranging Combination Study for Subcutaneous

  ViroPharma and Halozyme Therapeutics Announce Initiation of Phase 2b Dose
  Ranging Combination Study for Subcutaneous Administration of Cinryze® (C1
           esterase inhibitor [human]) With Hyaluronidase (rHuPH20)

PR Newswire

EXTON, Pa., Dec. 19, 2012

EXTON, Pa., Dec. 19, 2012 /PRNewswire/ --ViroPharma Incorporated (Nasdaq:
VPHM) and Halozyme Therapeutics (Nasdaq: HALO) announced today that
ViroPharma has initiated its Phase 2b double blind, multicenter, dose ranging
study to evaluate the safety and efficacy of subcutaneous (SC) administration
of Cinryze® (C1 esterase inhibitor [human)] in combination with Halozyme's
Enhanze™ technology, a proprietary drug delivery platform using Halozyme's
recombinant human hyaluronidase enzyme (rHuPH20), in adolescents and adults
with hereditary angioedema (HAE) for prevention of HAE attacks. Cinryze is
currently approved for intravenous (IV) administration.

"Routine prevention of attacks of hereditary angioedema is an important
therapeutic option for many patients," commented Prof. Dr. med. Marcus Maurer,
Department of Dermatology, Venerology and Allergy, Charite – University
Medicine Berlin, Germany and principal investigator of the study in Germany.
"While the current IV formulation of Cinryze is an important option for
patients seeking to prevent their attacks, a subcutaneous formulation could
represent a more convenient alternative for many."

This double blind, cross-over, dose ranging study will be conducted in
approximately 40 adolescent and adult subjects in the U.S. and Europe.
Qualified subjects will be randomized into one of two 8-week treatment
sequences of either 1000 U Cinryze with 24,000 U rHuPH20 or 2000 U Cinryze
with 48,000 U rHuPH20 as a twice weekly SC injection. Each subject will
participate for approximately 6 months. The primary efficacy endpoint is the
normalized number of angioedema attacks recorded during each treatment period.
In addition, several secondary endpoints will be assessed, including attack
severity, quality of life parameters using a novel angioedema tool, and number
of angioedema attacks requiring acute treatment. Additional information about
this Phase 2 subcutaneous Cinryze clinical trial can be found at

"Our goal is to optimize the delivery and convenience of self administration
of Cinryze, and we believe that the combination with rHuPH20 offers us the
best opportunity to achieve that goal," commented Jennifer Schranz, MD,
ViroPharma's vice president, clinical research. "The initiation of this
important phase 2 study is an essential step toward continually enhancing the
Cinryze experience for all patients who seek greater control over their
disease through routine prevention."

About Cinryze^® (C1 esterase inhibitor [human])

Cinryze is a highly purified, pasteurized and nanofiltered plasma-derived C1
esterase inhibitor product. In the U.S. and Canada, Cinryze is approved for
routine prophylaxis (prevention) against angioedema attacks in adolescent and
adult patients with HAE. In the E.U., the product is approved by the EMA for
the treatment and pre-procedure prevention of angioedema attacks in adults and
adolescents with hereditary angioedema (HAE), and routine prevention of
angioedema attacks in adults and adolescents with severe and recurrent attacks
of hereditary angioedema (HAE), who are intolerant to or insufficiently
protected by oral prevention treatments or patients who are inadequately
managed with repeated acute treatment. Cinryze is for intravenous use only.

Severe hypersensitivity reactions to Cinryze may occur. Thrombotic events
have occurred in patients receiving Cinryze, and in patients receiving
off-label high dose C1 inhibitor therapy. Monitor patients with known risk
factors for thrombotic events. With any blood or plasma derived product,
there may be a risk of transmission of infectious agents, e.g. viruses and,
theoretically, the CJD agent. The risk has been reduced by screening donors
for prior exposure to certain virus infections and by manufacturing steps to
reduce the risk of viral transmission including pasteurization and

The most common adverse reactions in clinical trials associated with Cinryze
were rash, headache, nausea, erythema, phlebitis and local reactions at the
injection site. Adverse events of sinusitis and upper respiratory infection
also were observed in clinical trials. No drug-related serious adverse events
(SAEs) were reported in clinical trials.

Please visit for the full U.S.
Prescribing Information; the prescribing information for other countries can
be found at

About Enhanze™ Technology

Enhanze is Halozyme's proprietary drug delivery platform based on the
Company's patented recombinant human hyaluronidase enzyme (rHuPH20). rHuPH20
acts by removing traditional limitations on the volume of drugs that can be
delivered subcutaneously (just under the skin). By using Enhanze, some drugs
that are administered intravenously may instead be delivered subcutaneously.
Enhanze may also benefit subcutaneous drugs by reducing the need for multiple
injections. This improved delivery may improve patient convenience and reduce
overall costs to the healthcare system.

About Hereditary Angioedema (HAE)

HAE is a rare, severely debilitating, life-threatening genetic disorder caused
by a deficiency of C1 inhibitor, a human plasma protein. This condition is the
result of a defect in the gene controlling the synthesis of C1 inhibitor. C1
inhibitor maintains the natural regulation of the contact, complement, and
fibrinolytic systems, that when left unregulated, can initiate or perpetuate
an attack by consuming the already low levels of endogenous C1 inhibitor in
HAE patients. Patients with C1 inhibitor deficiency experience recurrent,
unpredictable, debilitating, and potentially life threatening attacks of
inflammation affecting the larynx, abdomen, face, extremities and urogenital
tract. Patients with HAE experience approximately 20 to 100 days of
incapacitation per year. There are estimated to be at least 6,500 people with
HAE in the United States and at least 10,000 people in the European Union.

For more information on HAE, visit the HAEi's (International Patient
Organization for C1 Inhibitor Deficiencies) website at and the
U.S. HAE Association's website at:

About ViroPharma Incorporated

ViroPharma Incorporated is an international biopharmaceutical company
committed to developing and commercializing novel solutions for physician
specialists to address unmet medical needs of patients living with diseases
that have few if any clinical therapeutic options, including C1 esterase
inhibitor deficiency, pediatric epilepsy and C. difficile infection (CDI).
Our goal is to provide rewarding careers to employees, to create new
standards of care in the way serious diseases are treated, and to build
international partnerships with the patients, advocates, and health care
professionals we serve. ViroPharma's commercial products address diseases
including hereditary angioedema (HAE) and CDI; for prescribing information on
our products, please download the package inserts at

ViroPharma routinely posts information, including press releases, which may be
important to investors in the investor relations and media sections of our
company's website, The company encourages
investors to consult these sections for more information on ViroPharma and our

About Halozyme

Halozyme Therapeutics is a biopharmaceutical company dedicated to developing
and commercializing innovative products that advance patient care. With a
diversified portfolio of enzymes that target the extracellular matrix, the
Company's research focuses primarily on a family of human enzymes, known as
hyaluronidases, that increase the absorption and dispersion of biologics.
Halozyme's pipeline addresses therapeutic areas, such as diabetes, oncology
and dermatology that have significant unmet medical need. The Company markets
HYLENEX^® recombinant (hyaluronidase human injection) and has partnerships
with Roche, Baxter, ViroPharma and Intrexon. Halozyme is headquartered in San
Diego, CA. For more information on how we are innovating, please visit our
corporate website at

Forward Looking Statements

Certain statements in this press release contain forward-looking statements
that involve a number of risks and uncertainties. Forward-looking statements
provide our current expectations or forecasts of future events, including the
therapeutic indication and use, safety, efficacy, tolerability, convenience of
subcutaneous administration, and potential of Cinryze and our focus, goals,
strategy, research and development programs, and ability to develop
pharmaceutical products, commercialize pharmaceutical products, and execute on
our plans including clinical development activities with Cinryze related to
subcutaneous administration. There can be no assurance that that our clinical
program with Cinryze utilizing subcutaneous administration in combination with
rHuPH20 will yield positive results, be viewed by patients as more convenient
than IV administration, or support further development of Cinryze for
subcutaneous administration in combination with rHuPH20. The FDA or EMA may
view the data regarding subcutaneous administration of Cinryze in combination
with rHuPH20 as insufficient or inconclusive, request additional data, require
additional clinical studies, delay any decision past the time frames
anticipated by us, limit any approved indications, or deny the approval of
Cinryze for subcutaneous administration in combination with rHuPH20. These
factors, and other factors, including, but not limited to those described in
our annual report on Form 10-K for the year ended December 31, 2010 and 10-Q
filings for the quarters ended March 31, 2012, June 30, 2012, and September
30, 2012 filed with the Securities and Exchange Commission, could cause
future results to differ materially from the expectations expressed in this
press release. The forward-looking statements contained in this press release
are made as of the date hereof and may become outdated over time. ViroPharma
does not assume any responsibility for updating any forward-looking
statements. These forward looking statements should not be relied upon as
representing our assessments as of any date subsequent to the date of this
press release.

SOURCE ViroPharma Incorporated; Halozyme Therapeutics

Contact: ViroPharma Incorporated Contacts - Robert A. Doody Jr., Assistant
Director, Investor Relations, +1-610-321-6290; Halozyme Contact - Kurt
Gustafson, Chief Financial Officer, +1-858-704-8272
Press spacebar to pause and continue. Press esc to stop.