Baxter Completes Enrollment In Phase III Clinical Trial Of BAX 855, Extended Half-life Recombinant FVIII For Hemophilia A

DEERFIELD, Ill., Nov. 13, 2013 /PRNewswire/ -- Baxter International Inc. today announced it has completed enrollment in its Phase III clinical trial of BAX 855, an investigational extended half-life, recombinant factor VIII (rFVIII) treatment for hemophilia A. The ongoing trial is aimed at assessing the efficacy of the compound in reducing annualized bleed rates (ABR) in both prophylaxis and on-demand treatment schedules, and will also evaluate its safety and pharmacokinetic profile.

BAX 855 was designed based on the full-length ADVATE [Antihemophilic Factor (Recombinant) Plasma/Albumin-Free Method] molecule, a product with 10 years of real-world experience. The BAX 855 molecule was modified with PEGylation technology designed to extend its duration of activity in the body.

"The BAX 855 development program is a priority for Baxter as we evaluate the potential to provide an efficacious and safe treatment with an extended half-life for patients with hemophilia," said Anders Ullman, M.D., Ph.D., vice president of global research and development in Baxter's BioScience business. "We are focused first and foremost on strategies to address optimal efficacy and minimize patients' bleeding episodes, while at the same time delivering on the convenience of less frequent dosing for this population with severe disease."

The Phase II/III multi-center, open-label study called PROLONG-ATE is evaluating BAX 855 among 146 adult patients with previously-treated severe hemophilia A. Patients participating in PROLONG-ATE receive treatment twice weekly (45 IU/kg) and are followed for six months. The primary endpoint of the study is the annualized bleed rate (ABR) during the treatment period.  The study is also evaluating the safety and immunogenicity of the compound when administered on either prophylaxis and on-demand treatment regimens. Other outcome measures include number of infusions needed to treat bleeding episodes, time intervals between these episodes, pharmacokinetics and patient reported outcomes. To date, no inhibitors or safety issues have been reported in the study.

Based upon the results of the study, the company expects to complete the trial and file for regulatory approval late in 2014. Baxter is also initiating a continuation study for all patients who complete the pivotal Phase II/III study, and expects to initiate a study of BAX 855 among pediatric patients in 2014.

The treatment protocol is based on the results of a Phase I trial of BAX 855, assessing its safety, tolerability and pharmacokinetics. That trial found that the half-life (measuring the duration of activity of the drug in the body) of the investigational compound was approximately 1.5-fold higher compared to ADVATE. An extended half-life was achieved in all patients in the study using BAX 855, no patients developed inhibitors to either the base molecule, BAX 855 or to PEG, and no patients had allergic reactions. No treatment-related or serious adverse events were reported, and no patients withdrew from the study due to adverse events.

BAX 855 is built from the same native FVIII protein used in the production of ADVATE, and employs proprietary PEGylation technology from Nektar Therapeutics (NASDAQ:NKTR) designed to extend the duration of activity of proteins. PEGylation technology has been widely used in various approved treatments.

About ADVATE

ADVATE [Antihemophilic Factor (Recombinant) Plasma/Albumin-Free Method] is indicated for the control and prevention of bleeding episodes in adults and children (0-16 years) with hemophilia A.  ADVATE is also indicated for routine prophylaxis to prevent or reduce the frequency of bleeding episodes in adults and children (0-16 years) with hemophilia A.  ADVATE is not indicated for the treatment of von Willebrand disease.

ADVATE has a demonstrated efficacy profile and a low rate of inhibitor development.  ADVATE is a full-length (derived from the complete FVIII gene) recombinant FVIII product 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 treatments.

ADVATE is approved in 60 countries worldwide including the United States, Canada, 27 countries in the European Union, Argentina, Australia, Brazil, Chile, China, Colombia, Croatia, Ecuador, Hong Kong, Iceland, Iraq, Japan, Kuwait, Macau, Malaysia, Mexico, New Zealand, Norway, Panama, Puerto Rico, Serbia, Singapore, South Korea, Suriname, Switzerland, Taiwan, Tunisia, Turkey, Ukraine, Uruguay, and Venezuela.

Detailed 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, paresthesias, rash, flushing, face swelling, urticaria, dyspnea, and pruritus. Discontinue use if hypersensitivity symptoms occur and administer appropriate emergency treatment.

Carefully monitor patients treated with AHF products for the development of FVIII 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 FVIII inhibitor concentration.

The serious adverse reactions seen with ADVATE are hypersensitivity reactions and the development of high-titer inhibitors necessitating alternative treatments to FVIII.

The most common adverse reactions observed in clinical trials (frequency greater than or equal to 10 percent of subjects) were pyrexia, headache, cough, nasopharyngitis, vomiting, arthralgia, and limb injury.

Please see full prescribing information for ADVATE at: http://www.baxter.com/downloads/healthcare_professionals/products/ADVATE_PI.pdf

About Hemophilia A

Hemophilia is a rare genetic[1] blood clotting disorder and the most severe forms of the disease primarily affect males.[2] People living with hemophilia do not have enough of, or are missing, one of the blood clotting proteins naturally found in blood.[3] Two of the most common forms of hemophilia are A and B.  In people with hemophilia A, clotting factor VIII is not present in sufficient amounts or is absent.  Without enough FVIII, people with hemophilia can experience spontaneous, uncontrolled internal bleeding that is painful, debilitating, damaging to joints and potentially fatal.[4]  According to the World Federation of Hemophilia, it is estimated that more than 400,000 people in the world have hemophilia. [5]  All races and economic groups are affected equally.[6]

About Baxter in Hemophilia

Baxter has more than 60 years experience in hemophilia and has introduced a number of therapeutic firsts for hemophilia patients. Baxter has the broadest portfolio of hemophilia treatments in the industry and is able to meet individual therapy choices, providing a range of options at each treatment stage. The company's work focuses on optimizing hemophilia care and improving the lives of people worldwide living with bleeding disorders.

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 BAX 855 and related clinical studies, including expectations with regard to regulatory filings. 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: satisfaction of regulatory and other requirements; actions of regulatory bodies and other governmental authorities; additional clinical results; changes in laws and regulations; product quality or supply or patient safety issues; and other risks identified in Baxter's most recent filing on Form 10-K and other SEC filings, all of which are available on Baxter's website. Baxter does not undertake to update its forward-looking statements.  

Media Contact
Brian Kyhos
(224) 948-5353, [email protected]

Investor Contact
Mary Kay Ladone, (224) 948-3371

[1] How do you get hemophilia? World Federation of Hemophilia. Accessed on: June 3, 2013. Available at: http://www.wfh.org/en/page.aspx?pid=644
[2] Frequently Asked Questions About Hemophilia. World Federation of Hemophilia. Accessed on: June 3, 2013. Available at: http://www.wfh.org/en/page.aspx?pid=637
[3] What is Hemophilia? World Federation of Hemophilia. Accessed on: June 3, 2013. Available at: http://www.wfh.org/en/page.aspx?pid=646
[4] Lee, C. A. Hemophilia Care in the Modern World, in Current and Future Issues in Hemophilia Care (eds E.-C. Rodriguez-Merchan and L. A. Valentino), 2011.
[5] Treatment. World Federation of Hemophilia. Accessed on June 3, 2013. Available at: http://www.wfh.org/en/page.aspx?pid=642
[6] What is Hemophilia? Hemophilia Federation of America. Accessed on June 3, 2013. Available at:  http://www.hemophiliafed.org/bleeding-disorders/hemophilia/

SOURCE Nektar Therapeutics