General Information

Afstyla (Antihemophilic Factor (Recombinant), Single Chain) is a recombinant, antihemophilic factor.

Afstyla is specifically indicated for use in adults and children with hemophilia A (congenital Factor VIII deficiency) for:

On-demand treatment and control of bleeding episodes

Routine prophylaxis to reduce the frequency of bleeding episodes

Perioperative management of bleeding

Afstyla is supplied as a powder and solvent for reconstitution for intravenous injection. Please see drug label for recommended reconstitution and dosing schedules for each indication.

Clinical Results

FDA Approval

The FDA approval of Afstyla was based on on results from the AFFINITY clinical development program. AFFINITY includes two pivotal and one extension open-label multi-center studies evaluating the safety and efficacy of Afstyla in children, adolescents and adults with hemophilia A. The data from the AFFINITY clinical development program showed a median annualized spontaneous bleeding rate (AsBR) of 0.00 in both the adult and adolescent study as well as the 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 using Afstyla prophylactically. 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 the 13 adult or adolescent patients in the study who underwent surgical procedures (16 total surgeries), hemostatic efficacy of Afstyla was rated as excellent (15 times) or good (once).

Mechanism of Action

Afstyla (Antihemophilic Factor (Recombinant), Single Chain) is a recombinant, antihemophilic factor. Afstyla is a recombinant protein that replaces the missing Coagulation Factor VIII needed for effective hemostasis. Afstyla is a single polypeptide chain with a truncated B-domain that allows for a covalent bridge to link the Factor VIII heavy and light chains. Afstyla has demonstrated a higher VWF affinity relative to full-length rFVIII. VWF stabilizes Factor VIII and protects it from degradation. Activated Afstyla has an amino acid sequence identical to endogenous FVIIIa.