Baxter International Inc. and Halozyme Therapeutics, Inc. (Nasdaq: HALO) announced the start of a Phase III clinical trial of Baxter's GAMMAGARD LIQUID [Immune Globulin Intravenous] 10% (IGIV), marketed as KIOVIG in the European Union, with Halozyme's recombinant human hyaluronidase enzyme (rHuPH20, Enhanze(TM) Technology) for the treatment of primary immunodeficiency (PID). The purpose of this clinical trial is to evaluate the safety and efficacy and gain regulatory approval for the treatment of PID using GAMMAGARD LIQUID and rHuPH20 via subcutaneous (under the skin) injection at a single site.

GAMMAGARD LIQUID is currently administered intravenously (IV). Subcutaneous (SC) administration of GAMMAGARD LIQUID with Enhanze Technology is an investigational study and when approved could allow patients to receive a full monthly dose in a single injection site in their home setting.

"Baxter's work with Halozyme represents a commitment to innovation and, in particular, to advancing patient care with GAMMAGARD LIQUID," said Hartmut J. Ehrlich, M.D., vice president of Global Research and Development for Baxter's BioScience business.

"Entering Phase III clinical development is an important achievement for our hyaluronidase enzyme and for our collaboration with Baxter. We are pleased with the progress that has been made since our alliance began in September 2007," stated Jonathan Lim, M.D., President and CEO of Halozyme. "We look forward to continuing our strong working relationship with the Baxter team and to further advance this program."

This Phase III clinical study is a prospective, open-label, non-controlled design that will be conducted in 10-20 centers in the U.S. and Canada. The trial will evaluate the efficacy of GAMMAGARD LIQUID administered SC with rHuPH20 in the prevention of acute serious bacterial infections and will also assess pharmacokinetic parameters of SC and rHuPH20 compared to intravenous administration.

About GAMMAGARD LIQUID

GAMMAGARD LIQUID is indicated for the treatment of primary immunodeficiency disorders associated with defects in humoral immunity. These include but are not limited to congenital X-linked agammaglobulinemia, common variable immunodeficiency, Wiskott-Aldrich syndrome, and severe combined immunodeficiencies.

Important Safety Information

GAMMAGARD LIQUID is contraindicated in patients with known anaphylactic or severe hypersensitivity responses to Immune Globulin (Human). Patients with severe selective IgA deficiency (IgA < 0.05 g/L) may develop anti-IgA antibodies that can result in a severe anaphylactic reaction.

Immune Globulin Intravenous (Human) products have been reported to be associated with renal dysfunction, acute renal failure, osmotic nephrosis, and death. Patients predisposed to acute renal failure include patients with any degree of pre-existing renal insufficiency, diabetes mellitus, age greater than 65, volume depletion, sepsis, paraproteinemia, or patients receiving known nephrotoxic drugs. Especially in such patients, IGIV products should be administered at the minimum concentration available and the minimum rate of infusion practicable. While these reports of renal dysfunction and acute renal failure have been associated with the use of many of the licensed IGIV products, those containing sucrose as a stabilizer accounted for a disproportionate share of the total number.

Glycine, an amino acid, is used as a stabilizer. GAMMAGARD LIQUID does not contain sucrose.

GAMMAGARD LIQUID is made from human plasma. It may carry a risk of transmitting infectious agents, viruses, and theoretically, the Creutzfeldt-Jakob disease (CJD) agent.

Components used in the packaging of this product are latex-free.

Thrombotic events have been reported in association with IGIV. Patients at risk may include those with a history of atherosclerosis, multiple cardiovascular risk factors, advanced age, impaired cardiac output, and/or known or suspected hyperviscosity, hypercoagulable disorders, and prolonged periods of immobilization.

IGIV products can contain blood group antibodies that may cause a positive direct antiglobulin reaction and, rarely, hemolysis.

Aseptic meningitis syndrome (AMS) has been reported to occur infrequently in association with IGIV treatment. Discontinuation of IGIV treatment has resulted in remission of AMS within several days without sequelae.

Various mild and moderate reactions, such as headache, fever, fatigue, chills, flushing, dizziness, urticaria, wheezing or chest tightness, nausea, vomiting, rigors, back pain, chest pain, muscle cramps, and changes in blood pressure may occur with infusions of Immune Globulin Intravenous (Human).

About Baxter

Baxter International Inc. develops, manufactures and markets products that save and sustain the lives of people with hemophilia, immune disorders, infectious diseases, kidney disease, trauma, and other chronic and acute medical conditions. As a global, diversified healthcare company, Baxter applies a unique combination of expertise in medical devices, pharmaceuticals and biotechnology to create products that advance patient care worldwide.

About Halozyme Therapeutics, Inc.

Halozyme is a biopharmaceutical company developing and commercializing products targeting the extracellular matrix for the endocrinology, oncology, dermatology, and drug delivery markets. The company's portfolio of products and product candidates is based on intellectual property covering the family of human enzymes known as hyaluronidases. The company's Enhanze(TM) Technology is a novel drug delivery platform designed to increase the absorption and dispersion of biologics. Its key partnerships are with Roche to apply Enhanze Technology to Roche's biological therapeutic compounds for up to 13 targets and with Baxter to apply Enhanze Technology to Baxter's biological therapeutic compound, GAMMAGARD LIQUID 10%. In addition, the company has received FDA approval for two products: Cumulase(R), for use in in-vitro fertilization, and HYLENEX, for use as an adjuvant to increase the absorption and dispersion of other injected drugs and fluids. HYLENEX is partnered with Baxter International Inc. Halozyme also has a number of different enzymes in its portfolio that target significant areas of unmet medical need. For more information visit http://www.halozyme.com.

Safe Harbor Statement

In addition to historical information, the statements set forth above include forward-looking statements (including, without limitation, statements concerning the potential regulatory approval and the benefits of administering rHuPH20 with GAMMAGARD) that involve risk and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. The forward-looking statements are also identified through use of the words "believe," "enable," "may," "will," "could," "intends," "estimate," "anticipate," "plan," "predict," "probable," "potential," "possible," "should," "continue," and other words of similar meaning. Actual results could differ materially from the expectations contained in forward-looking statements as a result of several factors, including regulatory approval requirements and competitive conditions. These and other factors that may result in differences are discussed in greater detail in the companies' reports on Forms 10-K, 10-Q, and other filings with the Securities and Exchange Commission. Neither Baxter nor Halozyme undertakes to update its forward-looking statements.

Halozyme Therapeutics, Inc.
http://www.halozyme.com