Baxter Initiates Phase I Clinical Trial of Longer-Acting Recombinant FVIII Treatment for Hemophilia A

Baxter International Inc. (NYSE: BAX) today announced the dosing of the first patients in a Phase I clinical trial of its lead investigational candidate, BAX 855, a longer-acting (PEGylated) form of a full-length recombinant factor VIII (rFVIII) protein. BAX 855 is based on Baxter's ADVATE [Antihemophilic Factor (Recombinant) Plasma/Albumin-Free Method] full-length rFVIII molecule and plasma/albumin-free (PAF) manufacturing process.

The Phase I trial is a prospective, open-label study that will assess the safety, tolerability and pharmacokinetics of BAX 855 in previously-treated patients aged 12 years or older with severe hemophilia A. When used for prophylaxis, Baxter's ADVATE requires patients to infuse every two to three days to reduce the occurrence of bleeding episodes. This Phase I trial is the first step in assessing whether BAX 855 can be infused less frequently.

“This trial is designed to provide new insights about our investigational longer-acting FVIII molecule, BAX 855, with the ultimate goal of improving care for patients living with hemophilia A,” said Prof. Hartmut J. Ehrlich, M.D., vice president of global research and development in Baxter's BioScience business. “The Phase I results will serve as the foundation for advancing this important program through clinical development and determining whether BAX 855 can offer a treatment regimen requiring fewer infusions than ADVATE.”

BAX 855 employs Baxter's proprietary full-length plasma/albumin-free recombinant protein platform that does not contain any human or animal-derived additives. BAX 855 leverages Nektar Therapeutics' (NASDAQ: NKTR) proprietary PEGylation technology, which is designed to extend the duration of activity of proteins and larger molecules. Baxter and Nektar have a collaboration to develop PEGylated products designed to provide new long-acting therapies for hemophilia patients.

ADVATE was recently approved for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in patients with hemophilia A. With the inclusion of prophylaxis in the adult patient population, ADVATE became the only antihemophilic factor approved in the United States for prophylactic use in both children and adults. This approval was supported by a Phase IV prophylaxis study sponsored by Baxter demonstrating that ADVATE for routine prophylaxis significantly reduced median annual bleed rates (ABR) in hemophilia A patients. In the study, patients experienced 44 bleeds (per patient per year) during on-demand treatment compared to one bleed (per patient per year) while on either of the prophylactic regimens evaluated, a 98 percent reduction in annual bleed rate (p<0.0001). Nearly half (42 percent) of patients experienced zero bleeding episodes during one year on prophylactic therapy. Evaluable patients were those with at least 90 percent adherence to their prescribed prophylactic regimen.

About ADVATE

ADVATE was initially approved by the FDA in July 2003 for control and prevention of bleeding episodes in adults and children with hemophilia A.

ADVATE (derived from the complete FVIII gene) is a recombinant FVIII therapy that is processed without any blood-based additives. Because no blood-derived components are added at any stage of the manufacturing process, the potential risk of transmitting pathogens that may be carried in blood-based additives is eliminated. There have been no confirmed reports of transmission of HIV, HBV or HCV with rFVIII therapies.

ADVATE is approved in 53 countries worldwide including the United States, Canada, 27 countries in the European Union, Argentina, Australia, Brazil, Chile, Colombia, Croatia, Hong Kong, Iceland, Iraq, Japan, Macau, Malaysia, New Zealand, Norway, Panama, Puerto Rico, Serbia, Singapore, South Korea, Suriname, Switzerland, Taiwan, Uruguay and Venezuela. Since the initial approval of ADVATE, more than 10 billion international units have been distributed, and ADVATE is the number one chosen rFVIII worldwide.

ADVATE is an Antihemophilic Factor (Recombinant) indicated for:

• Control and prevention of bleeding episodes in adults and children (0-16 years) with hemophilia A
• Routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children (0-16 years) with hemophilia A
• Perioperative management in adults and children (0-16 years) with hemophilia A
• ADVATE is not indicated for the treatment of von Willebrand disease

Important Risk Information for ADVATE

ADVATE is contraindicated in patients with known anaphylaxis to mouse or hamster protein or other constituents of the product.

Allergic-type hypersensitivity reactions, including anaphylaxis, are possible and have been reported with ADVATE. Symptoms have manifested as dizziness, paresthesia, rash, flushing, face swelling, urticaria, dyspnea, and pruritis. Discontinue use if hypersensitivity symptoms occur and administer appropriate emergency treatment.

Carefully monitor patients treated with AHF products for the development of factor VIII inhibitors by appropriate clinical observations and laboratory tests. Inhibitors have been reported following administration of ADVATE predominantly in previously-untreated patients (PUPs) and previously minimally-treated patients (MTPs).

If expected plasma FVIII levels are not attained, or if bleeding is not controlled with an expected dose, perform an assay that measures factor VIII inhibitor concentration.

The serious adverse drug reactions (ADRs) seen with ADVATE are hypersensitivity reactions and the development of high-titer inhibitors necessitating alternative treatments to Factor VIII. The most common ADRs observed in clinical trials (frequency ≥ 10 percent of patients) were pyrexia, headache, cough, nasopharyngitis, vomiting, arthralgia, and limb injury.

Please see full prescribing information at www.advate.com or click here.

About Hemophilia

Hemophilia is a rare genetic blood clotting disorder.¹ People living with hemophilia do not have enough of, or are missing, one of the blood clotting proteins naturally found in blood.¹ Two of the most common forms of hemophilia are A and B and primarily affect males.² In people with hemophilia A, clotting factor VIII is not present in sufficient amounts or is absent.² Without enough FVIII, people with hemophilia can experience spontaneous, uncontrolled internal bleeding that is painful, debilitating, damaging to joints and potentially fatal.² People with hemophilia B (also called Christmas disease) do not have sufficient amounts of clotting factor IX.² In about 30 percent of cases, there is no family history of hemophilia and the condition is the result of a spontaneous gene mutation.³ According to the World Federation of Hemophilia, more than 400,000 people in the world have hemophilia.¹ All races and economic groups are affected equally.¹

About Baxter International Inc.

Baxter International Inc., through its subsidiaries, develops, manufactures and markets products that save and sustain the lives of people with hemophilia, immune disorders, cancer, 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.

This release includes forward-looking statements concerning a Phase I trial of the Company's investigational compound BAX 855, including with respect to expectations related to clinical outcomes. The statements are based on assumptions about many important factors, including the following, which could cause actual results to differ materially from those in the forward-looking statements: timely submission and approval of anticipated regulatory filings; clinical results validating the use of BAX 855 to treat patients with severe hemophilia A; satisfaction of regulatory and other requirements; actions of regulatory bodies and other governmental authorities; and other risks identified in Baxter's most recent filing on Form 10-K and other SEC filings, all of which are available on the company's website. Baxter does not undertake to update its forward-looking statements.