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First clinical trial site initiated in CSL Behring Phase II/III pivotal study of recombinant fusion protein linking coagulation factor IX with recombinant albumin
The site is located in Vienna, Austria. The prospective, open-label study will enroll adolescents and adults (12 – 65 years) who have hemophilia B.

CSL Behring has announced that the first site has been initiated in its global phase II/III, multi-center study to evaluate the safety, efficacy and pharmacokinetics of recombinant fusion protein linking coagulation factor IX with recombinant albumin (rIX-FP). The site is located in Vienna, Austria. The prospective, open-label study will enroll adolescents and adults (12 – 65 years) who have hemophilia B. CSL Behring, in collaboration with its parent company, CSL Limited (ASX:CSL), is developing rIX-FP for the prophylaxis and treatment of bleeding episodes in patients with congenital Factor IX (FIX) deficiency as part of the PROLONG-9FP clinical study program.

"The unmet medical need is great for a factor IX product with an extended half-life for use in treating people with hemophilia B, a life-long, debilitating clotting disorder," said Russell Basser, MD, Senior Vice President, Global Clinical R&D at CSL Behring. "Such a therapy can mean fewer injections for patients, and may enable or enhance prophylactic treatment. This would be an improved convenience that may result in a better quality of life for patients."

"We have entered a very exciting and promising era for patients with hemophilia," said Elena Santagostino, MD, Principal Investigator for the study. "A recombinant factor IX product with a longer half-life, such as the product that CSL Behring is developing, will have the potential to prevent bleeds in people who have hemophilia B. Today, these individuals generally must undergo frequent infusions of factor product to effectively manage their condition. Such a routine tends to present challenges; maintaining adherence to it can be difficult and one’s quality of life can therefore be impacted. The product in development today aims to reduce the number of infusions a patient with hemophilia must undergo. As treating physicians and clinical researchers, we are proud to be a part of this effort and look forward with great anticipation to the results of our research."

To date, the PROLONG-9FP program has established study sites in Austria, Bulgaria, France, Germany, Italy, Spain and in Israel. It is anticipated that in coming months additional trial sites will be established in the United States, Japan, and Russia.

CSL Behring and CSL have engineered rIX-FP to extend the half life of Factor IX while minimizing any tolerability issues. In the process, recombinant albumin—a protein with an inherently long half-life—is used as a fusion partner. A specifically designed linker connects the recombinant factor IX and recombinant albumin as a means of optimizing the efficacy of rIX-FP.

The Phase II/III study consists of a screening period, a pharmacokinetic (PK) evaluation period, followed by an approximate 12-month safety and efficacy evaluation period with rIX-FP. A surgical prophylaxis sub-trial is included. More information can be found at

About Hemophilia
Hemophilia is an inherited bleeding disorder characterized by prolonged or spontaneous bleeding, especially into the muscles, joints, or internal organs. In nearly all cases, it affects only males. The disease is caused by deficient or defective blood coagulation proteins known as factor VIII or IX. The most common form of the disease is hemophilia A, or classic hemophilia, in which the clotting factor VIII is either deficient or defective. Hemophilia B is characterized by deficient or defective factor IX. Hemophilia A affects approximately 1 in 5,000 to 10,000 people. Hemophilia B affects approximately 1 in 25,000 to 50,000 people. The recommended treatment for patients who are factor deficient is to treat by replacement factor therapy.

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


Sheila A. Burke, Director, Communications & Public Relations
Worldwide Commercial Operations
CSL Behring
610-878-4209 (o)
484-919-2618 (c)

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