0.8 ML asfotase alfa 100 MG/ML Injection [Strensiq]

INDICATIONS AND USAGE STRENSIQ ® is indicated for the treatment of patients with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP). STRENSIQ is a tissue nonspecific alkaline phosphatase indicated for the treatment of patients with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP). ( 1 )

DOSAGE AND ADMINISTRATION Perinatal/Infantile-Onset HPP ( 2.2 ) Recommended dosage regimen is 2 mg/kg administered subcutaneously three times per week, or 1 mg/kg administered six times per week. Injection site reactions may limit the tolerability of the six times per week regimen. The dose may be increased to 3 mg/kg three times per week for insufficient efficacy. Juvenile-Onset HPP ( 2.3 ) Recommended dosage regimen is 2 mg/kg administered subcutaneously three times per week, or 1 mg/kg administered six times per week. Injection site reactions may limit the tolerability of the six times per week regimen. Preparation and Weight-Based Dosing ( 2.4 ): Caution: Do not use the 80 mg/0.8 mL vial in pediatric patients weighing less than 40 kg because the systemic asfotase alfa exposure 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 full prescribing information for tables of weight-based dosing by treatment regimen. Administration ( 2.5 ): For subcutaneous injection only. Rotate injection sites. Do not administer to areas that are reddened, inflamed or swollen. 2.1 Recommendations Prior to STRENSIQ Treatment Initiate STRENSIQ under the supervision of a healthcare provider with appropriate medical monitoring and support measures [see Warnings and Precautions (5.1) ]. 2.2 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. 2.3 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) ]. 2.4 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) ] . 1. Determine the total weekly volume needed for the prescribed dosage based on the patient's weight and recommended dosage. Follow these steps to determine the patient dose. Total weekly dose (mg) = patient's weight (kg) × prescribed dose (mg/kg/week) Total injection volume (mL) per week = Total dose (mg/week) divided by the STRENSIQ concentration (40 mg/mL or 100 mg/mL). Note product concentrations are: 40 mg/mL (vial strengths 18 mg/0.45 mL, 28 mg/0.7 mL, 40 mg/mL) or 100 mg/mL (vial strength 80 mg/0.8 mL). Round total injection volume to the nearest hundredth of a mL Total number of vials per week = Total injection volume divided by vial volume (mL) 2. Determine the number of injection days per week (three or six per week). 3. Determine dose per injection day. Patient weights should be rounded to the nearest kilogram when determining dose. Use the following tables for guidance, for patients administering 2 mg/kg three times per week (Table 1), 1 mg/kg six times per week (Table 2) and for dose escalations to 3 mg/kg three times per week, recommended only for patients with perinatal/infantile-onset HPP [see Dosage and Administration (2.2) ] (Table 3). Table 1: Weight-Based Dosing for Administration of 2 mg/kg Three Times per Week Body Weight (kg) Do not use the 80 mg/0.8 mL vial of STRENSIQ in pediatric patients weighing less than 40 kg [see Clinical Pharmacology (12.3) ] . Dose to Inject Volume to Inject Vial Configuration 3 6 mg 0.15 mL 18 mg/0.45 mL 4 8 mg 0.2 mL 18 mg/0.45 mL 5 10 mg 0.25 mL 18 mg/0.45 mL 6 12 mg 0.3 mL 18 mg/0.45 mL 7 14 mg 0.35 mL 18 mg/0.45 mL 8 16 mg 0.4 mL 18 mg/0.45 mL 9 18 mg 0.45 mL 18 mg/0.45 mL 10 20 mg 0.5 mL 28 mg/0.7 mL 15 30 mg 0.75 mL 40 mg/1 mL 20 40 mg 1 mL 40 mg/1 mL 25 50 mg 1.25 mL Two 28 mg/0.7 mL vials 30 60 mg 1.5 mL Two 40 mg/1 mL vials 35 70 mg 1.75 mL Two 40 mg/1 mL vials 40 80 mg 0.8 mL 80 mg/0.8 mL 50 100 mg 1 mL Two 80 mg/0.8 mL vials 60 120 mg 1.2 mL When preparing a volume for injection greater than 1 mL, split the volume equally between two syringes, and administer two injections. When administering the two injections, use two separate injection sites. Two 80 mg/0.8 mL vials 70 140 mg 1.4 mL Two 80 mg/0.8 mL vials 80 160 mg 1.6 mL Two 80 mg/0.8 mL vials Table 2: Weight-Based Dosing for Administration of 1 mg/kg Six Times per Week Body Weight (kg) Do not use the 80 mg/0.8 mL vial of STRENSIQ in pediatric patients weighing less than 40 kg [see Clinical Pharmacology (12.3) ] . Dose to Inject Volume to Inject Vial Configuration 3 3 mg 0.08 mL 18 mg/0.45 mL 4 4 mg 0.1 mL 18 mg/0.45 mL 5 5 mg 0.13 mL 18 mg/0.45 mL 6 6 mg 0.15 mL 18 mg/0.45 mL 7 7 mg 0.18 mL 18 mg/0.45 mL 8 8 mg 0.2 mL 18 mg/0.45 mL 9 9 mg 0.23 mL 18 mg/0.45 mL 10 10 mg 0.25 mL 18 mg/0.45 mL 15 15 mg 0.38 mL 18 mg/0.45 mL 20 20 mg 0.5 mL 28 mg/0.7 mL 25 25 mg 0.63 mL 28 mg/0.7 mL 30 30 mg 0.75 mL 40 mg/1 mL 35 35 mg 0.88 mL 40 mg/1 mL 40 40 mg 1 mL 40 mg/1 mL 50 50 mg 0.5 mL 80 mg/0.8 mL 60 60 mg 0.6 mL 80 mg/0.8 mL 70 70 mg 0.7 mL 80 mg/0.8 mL 80 80 mg 0.8 mL 80 mg/0.8 mL 90 90 mg 0.9 mL Two 80 mg/0.8 mL vials 100 100 mg 1 mL Two 80 mg/0.8 mL vials Table 3: Weight-Based Dosing for Administration of 3 mg/kg Three Times per Week – Only for Perinatal/Infantile-Onset HPP A regimen of 3 mg/kg three times per week is recommended only for patients with perinatal/infantile-onset HPP [see Dosage and Administration (2.2) ] Body Weight (kg) Do not use the 80 mg/0.8 mL vial of STRENSIQ in pediatric patients weighing less than 40 kg [see Clinical Pharmacology (12.3) ] . Dose to Inject Volume to Inject Vial Configuration 3 9 mg 0.23 mL 18 mg/0.45 mL 4 12 mg 0.3 mL 18 mg/0.45 mL 5 15 mg 0.38 mL 18 mg/0.45 mL 6 18 mg 0.45 mL 18 mg/0.45 mL 7 21 mg 0.53 mL 28 mg/0.7 mL 8 24 mg 0.6 mL 28 mg/0.7 mL 9 27 mg 0.68 mL 28 mg/0.7 mL 10 30 mg 0.75 mL 40 mg/1 mL 15 45 mg 1.13 mL When preparing a volume for injection greater than 1 mL, split the volume equally between two syringes, and administer two injections. When administering the two injections, use two separate injection sites. Two 28 mg/0.7 mL vials 20 60 mg 1.5 mL Two 40 mg/1 mL vials 25 75 mg 1.88 mL Two 40 mg/1 mL vials 4. Take the unopened STRENSIQ vial(s) out of the refrigerator 15 to 30 minutes before injecting to allow the liquid to reach room temperature. Do not warm STRENSIQ in any other way (for example, do not warm it in a microwave or in hot water). 5. Inspect the solution in the vial(s) for particulate matter and discoloration. STRENSIQ is supplied as a clear, slightly opalescent or opalescent, colorless to slightly yellow aqueous solution; a few small translucent or white particles may be present. Discard any vial(s) not consistent with this appearance. 6. Assemble injection supplies. Administer STRENSIQ using sterile disposable 1 mL syringes and ½ inch injection needles, between 25 to 29 gauge are recommended. The use of two different gauge needles is recommended, a larger bore needle (e.g. 25 gauge) for withdrawal of the medication, and a smaller bore needle (e.g. 29 gauge) for the injection. For doses greater than 1 mL, the injection volume should be split equally between

WARNINGS AND PRECAUTIONS Lipodystrophy: Localized reactions were reported after several months of treatment; follow proper injection technique and rotate injection sites. ( 5.2 ) Ectopic Calcifications (eye and kidneys): Monitor using ophthalmologic examinations and renal ultrasounds at baseline and periodically during treatment. ( 5.3 ) Possible Immune-Mediated Clinical Effects: Evaluate patients for antibody formation if clinically indicated. ( 5.4 ) 5.1 Hypersensitivity Reactions Including Anaphylaxis Life-threatening hypersensitivity reactions, including anaphylaxis, have been reported in patients treated with enzyme replacement therapies, including STRENSIQ. Signs and symptoms consistent with anaphylaxis included difficulty breathing, choking sensation, nausea, periorbital edema, and dizziness. These reactions have occurred within minutes after subcutaneous administration of STRENSIQ and have been observed more than 1 year after treatment initiation. Other hypersensitivity reactions have also been reported in STRENSIQ-treated patients, including vomiting, fever, headache, flushing, irritability, chills, erythema, rash, pruritus and oral hypoesthesia [see Adverse Reactions (6.1) ] . Anaphylaxis has occurred during the early course of enzyme replacement therapy and after extended duration of therapy. Initiate STRENSIQ under the supervision of a healthcare provider with appropriate medical monitoring and support measures. If a severe hypersensitivity reaction (e.g., anaphylaxis) occurs, discontinue STRENSIQ and immediately initiate appropriate medical treatment, including use of epinephrine. Consider the risks and benefits of re-administering STRENSIQ to individual patients following a severe reaction. If the decision is made to re-administer the product, monitor patients for a reoccurrence of signs and symptoms of a severe hypersensitivity reaction. Inform patients of the symptoms of life-threatening hypersensitivity reactions, including anaphylaxis and to seek immediate medical care should symptoms occur. 5.2 Lipodystrophy Localized lipodystrophy, including lipoatrophy and lipohypertrophy, has been reported at injection sites after several months in patients treated with STRENSIQ in clinical trials [see Adverse Reactions (6.1) ] . Advise patients to follow proper injection technique and to rotate injection sites [see Dosage and Administration (2.5) ] . 5.3 Ectopic Calcifications Patients with HPP are at increased risk for developing ectopic calcifications. Events of ectopic calcification, including ophthalmic (conjunctival and corneal) and renal (nephrocalcinosis, nephrolithiasis), have been reported in the clinical trial experience with STRENSIQ. There was insufficient information to determine whether or not the reported events were consistent with the disease or due to STRENSIQ. No visual changes or changes in renal function were reported resulting from the occurrence of ectopic calcifications. Ophthalmology examinations and renal ultrasounds are recommended at baseline and periodically during treatment with STRENSIQ to monitor for signs and symptoms of ophthalmic and renal ectopic calcifications and for changes in vision or renal function. 5.4 Possible Immune-Mediated Clinical Effects In clinical trials, most STRENSIQ-treated patients developed anti-asfotase alfa antibodies and neutralizing antibodies which resulted in reduced systemic exposure of asfotase alfa [see Immunogenicity (6.2) ]. In postmarketing reports, some STRENSIQ-treated patients with initial therapeutic response subsequently developed recurrence and worsening in disease-associated laboratory and radiographic biomarkers (some in association with neutralizing antibodies) suggesting possible immune-mediated effects on STRENSIQ's pharmacologic action resulting in disease progression [see Adverse Reactions (6.3) ] . The effect of anti-asfotase alfa antibody formation on the long-term efficacy of STRENSIQ is unknown. There are no marketed anti-asfotase alfa antibody tests. If patients experience progression of HPP symptoms or worsening of disease-associated laboratory and imaging biomarkers after a period of initial therapeutic response to STRENSIQ, consider obtaining anti-asfotase alfa antibody testing by contacting STRENSIQ Medical Information at Alexion at 1-888-765-4747 or by email at medinfo@alexion.com. Close clinical follow up is recommended.

CONTRAINDICATIONS None. None. ( 4 )

Mechanism of Action HPP is caused by a deficiency in TNSALP enzyme activity, which leads to elevations in several TNSALP substrates, including inorganic pyrophosphate (PPi). TNSALP is a metallo-enzyme that catalyzes the hydrolysis of phosphomonoesters with release of inorganic phosphate and alcohol. Elevated extracellular levels of PPi block hydroxyapatite crystal growth which inhibits bone mineralization and causes an accumulation of unmineralized bone matrix which manifests as rickets and bone deformation in infants and children and as osteomalacia (softening of bones) once growth plates close, along with muscle weakness. Replacement of the TNSALP enzyme upon STRENSIQ treatment reduces the enzyme substrate levels.