Data presented by CSL Behring today suggest that the bioavailability of immunoglobulin G (IgG) therapies is consistent when patients with primary immunodeficiencies switch from one IgG product to another by the subcutaneous route. The analysis, which was presented at the 2012 American Academy of Allergy, Asthma and Immunology annual meeting, was a joint effort between CSL Behring and physicians at University Hospital of Wales, Cardiff, UK and University of South Florida, St. Petersburg, USA.

Based on an analysis of published data, the study found that bioavailability – the percentage of unchanged drug that reaches the circulation – was similar among four subcutaneous IgG (SCIg) preparations and all fell within the range of 66.7± 2.7 percent as compared to intravenous IgG. In the United States study, mean serum IgG level following SCIg administration did not differ significantly between Hizentra® (Immune Globulin Subcutaneous [Human]) and Vivaglobin® at the recommended dose dosages (1139±249 mg/dl and 1158±311 mg/dl, respectively). In the European Union, mean serum IgG levels were not significantly different between all tested SCIg products and Hizentra® when the same doses were administered (843±138mg/dl and 833±125mg/dl, respectively).

“Maintaining a consistent level of IgG in the blood is important for patients with primary immunodeficiencies in order to prevent infections,” said John W. Sleasman, MD, Chief of the Division of Pediatric Allergy, Immunology and Rheumatology at the University of South Florida. “This analysis provides reassurance that regardless of current treatment – intravenous or subcutaneous – patients can switch IgG products without undue concern about dosing or therapeutic IgG levels.”

“This analysis furthers the understanding of bioavailability among Ig therapy options, an important consideration for patients and physicians as they evaluate which product is best suited to an individual patient’s therapeutic and lifestyle needs,” said Dr. Mel Berger, Senior Medical Director, Immunology Research and Development at CSL Behring. “CSL Behring will continue to advance research on how best to use innovative SCIg treatments such as Hizentra® to ensure patients can achieve steady-state serum IgG levels and consistent symptom control with Ig therapy that fits into their lives.”

About the Analysis
Published clinical data from the United States and the European Union were analyzed and percent bioavailability calculated using area under the curve (AUC) measurements obtained from the studies.

About Primary Immunodeficiencies
Primary immunodeficiency (PI) is a group of more than 150 diseases that affect the cells, tissues and proteins of the immune system. In people with PI, the immune system is either absent or functioning inadequately, leaving them more susceptible to infection. For individuals with PI – many of them children – infections may not improve with treatment as expected, and may keep returning. As a result, patients may face repeated rounds of antibiotics or be hospitalized for treatment. Repeated infections can lead to organ damage, which, over time, can become life-threatening. Collectively, PIs affect an estimated 10 million people worldwide, and the incidence is estimated to be 1 in 10,000. For more information on PI, please visit www.cslbehring.com or AAAAI, or contact the leading PI patient advocate groups in the U.S., the Immune Deficiency Foundation and the Jeffrey Modell Foundation.

About Hizentra®
Hizentra®(Immune Globulin Subcutaneous [Human]), the first and only 20 percent SCIg developed for subcutaneous use, is approved in the United States and is registered in the EU and Switzerland. It is stable at 25° C (77° F) for 30 months due to formulation with L-proline. In the United States, Hizentra® is indicated for the treatment of patients with primary immunodeficiency (PI), and contraindicated in individuals with a history of anaphylactic or severe systemic response to immune globulin preparations or components of Hizentra®, and in persons with selective immunoglobulin A deficiency who have known antibody against IgA and a history of hypersensitivity. The most common drug-related adverse reactions, observed in 5 percent or more of subjects in the U.S. clinical study, were local injection-site reactions, headache, vomiting, pain, and fatigue. For more information, including full U.S. prescribing information, visit www.hizentra.com.

Hizentra® is part of the immunoglobulin (Ig) franchise for CSL Behring. This comprehensive Ig product portfolio also includes the first U.S. FDA-approved subcutaneous immunoglobulin and the first proline-stabilized intravenous immunoglobulin. CSL Behring manufactures Hizentra® at its state-of-the art facility in Bern, Switzerland, where advanced technologies are applied to further help ensure product safety and ample supply. This facility represents the long-term commitment of CSL Behring to global Ig markets.

Important Safety Information
Hizentra® is indicated as replacement therapy for the treatment of patients with primary humoral immunodeficiency.

Hizentra® is contraindicated in individuals with a history of anaphylactic or severe systemic response to immune globulin preparations or components of Hizentra®, and in persons with selective immunoglobulin A deficiency who have known antibody against IgA and a history of hypersensitivity. If anaphylactic reactions are suspected, administration should be discontinued immediately and the patient treated as medically appropriate. Because Hizentra® contains the stabilizer L-proline, it is also contraindicated in patients with hyperprolinemia. Hizentra® should be administered subcutaneously only. Hizentra® is derived from human plasma. The risk of transmission of infectious agents including viruses and, theoretically, the Creutzfeldt-Jakob disease (CJD) agent, cannot be eliminated completely. The most common drug-related adverse reactions, observed in 5 percent or more of subjects in the clinical study, were local injection-site reactions, headache, vomiting, pain, and fatigue. Monitor patients for reactions associated with IVIg treatment that might occur with Hizentra®, including renal dysfunction/failure, thrombotic events, aseptic meningitis syndrome (AMS), hemolysis and transfusion-related acute lung injury (TRALI).

For full U.S. prescribing information, visit www.hizentra.com/consumer/prescribing-information.aspx.

About CSL Behring
CSL Behring is a leader in the plasma protein therapeutics industry. Committed to saving lives and improving the quality of life for people with rare and serious diseases, the company manufactures and markets a range of plasma-derived and recombinant therapies worldwide. CSL Behring therapies are indicated for the treatment of coagulation disorders including hemophilia and von Willebrand disease, primary immune deficiencies, hereditary angioedema and inherited respiratory disease. The company's products are also used in cardiac surgery, organ transplantation, burn treatment and to prevent hemolytic diseases in newborns. CSL Behring operates one of the world's largest plasma collection networks, CSL Plasma. CSL Behring is a subsidiary of CSL Limited (ASX: CSL), a biopharmaceutical company headquartered in Melbourne, Australia. For more information, visit www.cslbehring.com.

Sheila A. Burke
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Sheila.burke@cslbehring.com

Etanjalie Ayala
Weber Shandwick
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212-445-8225
eayala@webershandwick.com