For: Hypophosphatasia
Strensiq (asfotase alfa) is a tissue nonspecific alkaline phosphatase enzyme replacement therapy indicated for the treatment of patients with perinatal, infantile and juvenile-onset hypophosphatasia (HPP). STRENSIQ- asfotase alfa solution
Alexion Pharmaceuticals Inc.
1 INDICATIONS AND USAGE
STRENSIQ� is indicated for the treatment of patients with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP).
2 DOSAGE AND ADMINISTRATION
2.1 Dosage for Perinatal/Infantile-Onset HPP
The recommended dosage regimen of STRENSIQ for the treatment of perinatal/infantile-onset HPP is 6 mg/kg per week administered subcutaneously as either:
2 mg/kg three times per week, or
1 mg/kg six times per week. Injection site reactions may limit the tolerability of the six times per week regimen [see Adverse Reactions (6.1)].
The dose of STRENSIQ may be increased for lack of efficacy (e.g., no improvement in respiratory status, growth, or radiographic findings) up to 9 mg/kg per week administered subcutaneously as 3 mg/kg three times per week.
2.2 Dosage for Juvenile-Onset HPP
The recommended dosage regimen of STRENSIQ for the treatment of juvenile-onset HPP is 6 mg/kg per week administered subcutaneously as either:
2 mg/kg three times per week, or
1 mg/kg six times per week. Injection site reactions may limit the tolerability of the six times per week regimen [see Adverse Reactions (6.1)].
2.3 Preparation and Weight-Based Dosing Tables
Caution: Do not use the 80 mg/0.8 mL vial of STRENSIQ in pediatric patients weighing less than 40 kg because the systemic exposure of asfotase alfa achieved with the 80 mg/0.8 mL vial (higher concentration) is lower than that achieved with the other strength vials (lower concentration). A lower exposure may not be adequate for this subgroup of patients [see Dosage Forms and Strengths (3), Clinical Pharmacology (12.3)].
DOSAGE FORMS AND STRENGTHS
STRENSIQ is supplied as a sterile, preservative-free, nonpyrogenic, clear, slightly opalescent or opalescent, colorless to slightly yellow aqueous solution; few small translucent or white particles may be present. The product is available as:
Injection: 18 mg/0.45 mL, 28 mg/0.7 mL, 40 mg/mL, or 80 mg/0.8 mL solution in single-use vials
DESCRIPTION
STRENSIQ is a formulation of asfotase alfa, which is a soluble glycoprotein composed of two identical polypeptide chains. Each chain contains 726 amino acids with a theoretical mass of 161 kDa. Each chain consists of the catalytic domain of human tissue non-specific alkaline phosphatase (TNSALP), the human immunoglobulin G1 Fc domain and a deca-aspartate peptide used as a bone targeting domain. The two polypeptide chains are covalently linked by two disulfide bonds.
STRENSIQ is a tissue nonspecific alkaline phosphatase produced by recombinant DNA technology in a Chinese hamster ovary cell line. TNSALP is a metallo-enzyme that catalyzes the hydrolysis of phosphomonoesters with release of inorganic phosphate and alcohol. Asfotase alfa has a specific activity of 620 to 1250 units/mg. One activity unit is defined as the amount of asfotase alfa required to form 1 �mol of p-nitrophenol from pNPP per minute at 37�C.
STRENSIQ (asfotase alfa) is a sterile, preservative-free, nonpyrogenic, clear, slightly opalescent or opalescent, colorless to slightly yellow, with few small translucent or white particles, aqueous solution for subcutaneous administration. STRENSIQ is supplied in glass single-use vials containing asfotase alfa; dibasic sodium phosphate, heptahydrate; monobasic sodium phosphate, monohydrate; and sodium chloride at a pH between 7.2 and 7.6.