CSL Behring announced that Afstyla [Antihemophilic Factor (Recombinant), Single Chain], its novel long-lasting recombinant factor VIII single-chain therapy for adults and children with haemophilia A, is now available nationwide. Afstyla is the first and only single-chain product for haemophilia A specifically designed for long-lasting protection from bleeds with two to three times weekly dosing.

Afstyla was approved by the US Food and Drug Administration (FDA) in May for use in children and adults with haemophilia A for routine prophylaxis to reduce the frequency of bleeding episodes; on-demand treatment and control of bleeding episodes; and the perioperative management of bleeding. In clinical trials, patients undergoing prophylaxis with Afstyla experienced a median annualized spontaneous bleeding rate (AsBR) of 0.00. Once activated, Afstyla is identical to natural factor VIII. Clinical trials of Afstyla demonstrated a strong safety profile with no inhibitors observed.

“We are proud to add Afstyla to our leading portfolio of bleeding disorder products and are particularly excited about the positive impact that treatment with Afstyla can have on the lives of patients with haemophiliaA,” said Jerry Powell, M.D., medical director, North America Commercial Operations, CSL Behring. “Afstyla is the second product from our innovative recombinant factor development program approved by the FDA in 2016. In March, Idelvion [Coagulation Factor IX (Recombinant), Albumin Fusion Protein], the first and only recombinant albumin fusion protein for haemophilia B, was approved by the FDA. Both Afstyla and Idelvion deliver on our promise to develop and provide innovative specialty biotherapies that help people with serious medical conditions live full lives.”

Afstyla is available in five vial sizes: 250, 500, 1000, 2000 and 3000 international units of factor VIII. The product can be stored in the refrigerator or at room temperature (2-25°C; 36-77°F).

Primarily affecting males, haemophilia A is a congenital bleeding disorder characterized by deficient or defective factor VIII. People with haemophilia A may experience prolonged or spontaneous bleeding, especially into the muscles, joints or internal organs. According to the United States Centers for Disease Control and Prevention (CDC), the condition affects approximately 1 in 6,000 male births.

FDA approval of Afstyla was based on results from the AFFINITY clinical development program. AFFINITY included two pivotal and one extension open-label multi-center studies evaluating the safety and efficacy of Afstyla in children, adolescents and adults with haemophilia A.

Data from the AFFINITY clinical development program show a median annualized spontaneous bleeding rate (AsBR) of 0.00 in prophylactic use for both the adult and adolescent study and pediatric study. The median annualized bleeding rate (ABR) was 1.14 in adult and adolescent patients, and 3.69 in children less than 12 years of age. Of 1,195 bleeds treated in the pivotal study (848 in adults and adolescents; 347 in children), 94 percent of bleeds in adult and adolescent patients and 96 percent of bleeding events in pediatric patients were effectively controlled with no more than two infusions of Afstyla  weekly; 81 percent of bleeds in adult and adolescent patients and 86 percent of bleeding events in pediatric patients were effectively controlled by only one infusion. The majority of bleeding events treated with Afstyla  (94 percent in adults and adolescents; 96 percent in children) were rated as excellent or good. Of 16 total surgical procedures (involving 13 adult or adolescent patients in the study), the hemostatic efficacy of Afstyla  was rated as excellent (15 times) or good (once). The most common adverse reactions reported in clinical trials were dizziness and hypersensitivity.

Afstyla (also known as rVIII-Single Chain) for haemophilia A is CSL Behring’s recombinant single-chain factor VIII specifically designed for increased molecular stability and long duration of action. Afstyla uses a covalent bond that forms one structural entity, a single polypeptide-chain, to improve the stability of factor VIII and provide longer-lasting factor VIII activity. Regulatory agencies in Europe, Switzerland and Australia are currently reviewing CSL Behring’s license applications for Afstyla.