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IDELVION® – CSL Behring’s Innovative Therapy for Hemophilia B Patients – Receives 7 Years of Marketing Exclusivity from the U.S. Food and Drug Administration
CSL Behring announced today it has been granted seven years of marketing exclusivity by the U.S. Food and Drug Administration (FDA) for IDELVION® [Coagulation Factor IX (Recombinant), Albumin Fusion Protein].

CSL Behring announced today it has been granted seven years of marketing exclusivity by the U.S. Food and Drug Administration (FDA) for IDELVION® [Coagulation Factor IX (Recombinant), Albumin Fusion Protein]. In clinical trials, IDELVION maintained factor IX activity levels above 5 percent over 14 days, resulting in a median annualized spontaneous bleeding rate (AsBR) of 0.00. The FDA grants marketing exclusivity for innovative, first-to-market orphan drugs, such as IDELVION.

“CSL Behring is pleased with the FDA’s decision to grant orphan drug marketing exclusivity for IDELVION. This milestone acknowledges our promise to develop innovative therapies for patients with hemophilia B and other rare and serious conditions,” said Jerry Powell, M.D., Medical Director, North America Commercial Operations, CSL Behring. “We continuously work to deliver on our promise to improve the care of patients with bleeding disorders around the world.”

IDELVION was approved by the FDA in March 2016 for use in children and adults with hemophilia B (congenital factor IX deficiency) for: on-demand control and prevention of bleeding episodes, perioperative management of bleeding and routine prophylaxis to prevent or reduce the frequency of bleeding episodes. IDELVION is the first and only factor IX albumin fusion therapy that delivers high-level protection with up to 14-day dosing in appropriate patients 12 and older. This extended dosing interval has been achieved while maintaining high levels of factor activity -- above 5 percent over 14 days at the highest dose -- thereby reducing the monthly number of units needed for prophylaxis therapy. IDELVION is currently available to patients nationwide.

FDA approval of IDELVION was based on results from the PROLONG-9FP clinical development program, which included a global Phase II/III pivotal clinical study. Data from this study were recently published in Blood.

About Orphan Drug Status

Under the Orphan Drug Act (ODA), the FDA Office of Orphan Products Development (OOPD) may grant orphan drug designation to drugs or biologics intended for the safe and effective treatment, diagnosis or prevention of rare diseases/disorders that affect fewer than 200,000 people in the U.S., or that affect more than 200,000 persons but are not expected to recover the costs of developing and marketing a treatment drug. The first orphan designated product receiving FDA approval for the orphan indication is eligible to receive a seven-year marketing exclusivity period for the orphan indication. CSL Behring received orphan drug designation for IDELVION in 2012. IDELVION will be the only recombinant factor IX albumin fusion protein for treating hemophilia B that the FDA will approve for seven years. Other therapies for hemophilia B, using alternative technologies or pursuing different indications, may still receive FDA approval.

About Hemophilia B

Hemophilia B is a congenital bleeding disorder characterized by deficient or defective factor IX; nearly all affected patients are male. People with hemophilia B may experience prolonged or spontaneous bleeding, especially into the muscles, joints, or internal organs. According to the U.S. Centers for Disease Control and Prevention, the condition affects approximately one in 25,000 male births.


PROLONG-9FP includes Phase I through Phase III open-label, multicenter studies evaluating the safety and efficacy of IDELVION in children and adults (ages 1 to 61 years) with hemophilia B (factor IX levels ≤2%).The data from PROLONG-9FP showed median annualized spontaneous bleeding rates (AsBR) of 0.00 and factor IX activity levels above 5 percent in patients using IDELVION prophylactically. This result was achieved for both 14-day dosing and 7-day dosing. The data for on-demand therapy showed that 94 percent of bleeds were controlled with one infusion, while 99 percent were controlled with one or two infusions. The most common adverse reaction in clinical trials was headache.


CSL Behring engineered IDELVION to extend the half-life of recombinant factor IX through fusion with recombinant albumin. CSL Behring selected recombinant albumin as its fusion partner for its coagulation factor proteins due to its long physiological half-life.

IDELVION is also approved in the European Union and Canada. Regulatory agencies in Australia, Switzerland and Japan are also currently reviewing CSL Behring’s marketing applications for IDELVION.

For more information about IDELVION, including full prescribing information, please visit

Important Safety Information

IDELVION®, Coagulation Factor IX (Recombinant), Albumin Fusion Protein (rIX-FP), is indicated in children and adults with hemophilia B (congenital factor IX deficiency) for:

  • On-demand control and prevention of bleeding episodes
  • Perioperative management of bleeding
  • Routine prophylaxis to prevent or reduce the frequency of bleeding episodes

IDELVION is not indicated for induction of immune tolerance in patients with hemophilia B.

IDELVION is contraindicated in patients who have had life-threatening hypersensitivity to the product or its components, including hamster proteins.

IDELVION is for intravenous use only. IDELVION can be self-administered or administered by a caregiver with training and approval from a healthcare provider or hemophilia treatment center. Higher dose per kilogram body weight or more frequent dosing may be needed for pediatric patients.

Hypersensitivity reactions, including anaphylaxis, are possible. Advise patients who self-administer to immediately report symptoms of hypersensitivity, including angioedema, chest tightness, hypotension, generalized urticaria, wheezing, and dyspnea. If symptoms occur, discontinue IDELVION and administer appropriate treatment.

Development of neutralizing antibodies (inhibitors) to IDELVION may occur. If expected factor IX activity plasma levels are not attained or bleeding is not controlled with appropriate dose, perform an assay to measure factor IX inhibitor concentration. Factor IX activity assay results may vary with the type of activated partial thromboplastin time reagent used.

Thromboembolism (e.g., pulmonary embolism, venous thrombosis, and arterial thrombosis) can occur when using factor IX-containing products. In addition, nephrotic syndrome has been reported following immune tolerance induction in hemophilia B patients with factor IX inhibitors and allergic reactions to factor IX.

The most common adverse reaction (incidence ≥1%) reported in clinical trials was headache.

About CSL Behring

CSL Behring is a global biotherapeutics leader which is driven by its promise to save lives. Focused on serving patients’ needs by using the latest technologies, we develop and deliver innovative therapies that are used to treat coagulation disorders, primary immune deficiencies, hereditary angioedema, inherited respiratory disease, and neurological disorders. The company's products are also used in cardiac surgery, organ transplantation, burn treatment and to prevent hemolytic disease of the newborn.

CSL Behring operates one of the world's largest plasma collection networks, CSL Plasma. The parent company, CSL Limited (ASX:CSL), headquartered in Melbourne, Australia, employs more than 16,000 people with operations in more than 30 countries. For more information visit and follow us on For more information about CSL Behring visit or follow us at



Greg Healy
CSL Behring
Office: 610-878-4841
Mobile: 610-906-4564

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