Strensiq

Dosage Forms & Strengths

SC injectable solution

• 80 mg/0.8mL (use for patients who weigh >40kg)

Hypophosphatasia

Indicated for perinatal/infantile- and juvenile-onset hypophosphatasia (HPP)

6 mg/kg/week SC administered as 2 mg/kg given 3 x/week or 1 mg/kg given 6 x/week

Injection site reactions may limit the tolerability of the 6 x/week regimen

Note: For perinatal/infantile-onset HPP, the dose may be increased for lack of efficacy (eg, no improvement in respiratory status, growth, or radiographic findings) up to 9 mg/kg per week administered SC as 3 mg/kg 3 x/week

Dosage Forms & Strengths

SC injectable solution

• 18mg/0.45mL
• 28mg/0.7mL
• 40mg/mL
• 80 mg/0.8mL (use for patients who weigh >40kg)

Hypophosphatasia

Indicated for perinatal/infantile- and juvenile-onset hypophosphatasia (HPP)

6 mg/kg/week SC administered as 2 mg/kg given 3 x/week or 1 mg/kg given 6 x/week

Injection site reactions may limit the tolerability of the 6 x/week regimen

Note: For perinatal/infantile-onset HPP, the dose may be increased for lack of efficacy (eg, no improvement in respiratory status, growth, or radiographic findings) up to 9 mg/kg per week administered SC as 3 mg/kg 3 x/week

Dosing Considerations

Caution: Do not use the 80-mg/0.8 mL vial in pediatric patients weighing <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

SC Preparation

Determine the volume needed for the prescribed weight-based dose

• Total dose (mg) = patient’s weight (kg) x prescribed dose (mg/kg)
• Total injection volume (mL) = Total dose (mg) divided by concentration (40 mg/mL or 80 mg/0.8 mL)
• Round total injection volume to the nearest hundredth of a mL
• Total number of vials = Total injection volume divided by vial volume (mL)
• If the volume for injection is >1 mL, split the volume equally between 2 syringes, and administer as 2 SC injections (use separate injection sites)
• See prescribing information for detailed weight-based charts

Prepare the syringe(s)

• Inspect the solution in the vial(s) for particulate matter and discoloration
• Should appear as a clear, slightly opalescent or opalescent, colorless to slightly yellow aqueous solution; few small translucent or white particles may be present
• Discard any vials(s) not consistent with this appearance
• Assemble injection supplies
• Administer using sterile disposable 1-mL syringes and 0.5-inch injection needles, from 25- to 29-gauge
• Remove vial cap, aseptically prepare the vial, and insert the syringe into the vial to withdraw the prescribed dose for administration
• Remove any air bubbles in the syringe and verify the correct dose

SC Administration

For SC administration only

Administer within 1 hr upon removal of the vial(s) from refrigeration

Rotate the injection from among the following sites to reduce the risk of lipodystrophy: abdominal area, thigh, or deltoid

Do NOT administer injections in areas that are reddened, inflamed, or swollen

Inject SC into the determined site and properly dispose of the needle

Vials are single use only; discard any unused product

Storage

Store refrigerated 2-8°C (36-46°F)

Store unopened vials in the original carton to protect from light

Do not freeze or shake

Use Strensiq exactly as prescribed.

Strensiq comes as an injection to be given under the skin. It is typically injected three or six times per week.

Your healthcare provider will tell you how much Strensiq to use and when to use it.

Your healthcare provider may change your dose if needed.

Change (rotate) your injection site with each injection. Do not use the same injection site for each injection.

To inject Strensiq, follow these instructions:

1. Wash your hands.
2. Check the liquid in the vial of Strensiq. Do not use if it is discolored or contains large particles in it.
3. Pull back the plunger on your syringe until the black tip reaches the line for your prescribed dose.
4. Push the needle through the rubber stopper into the vial.
5. Turn the vial and syringe upside down and push the plunger all the way in, inserting air into the vial.
6. Slowly pull the plunger back to the line slightly beyond the correct dose that you need.
7. With the needle still in the vial, slowly push the plunger up until the top of it reaches the line for your prescribed dose.
8. Pull the syringe out of the vial. If there are air bubbles, tap the syringe gently with your finger to remove them.
9. Clean your injection site with an alcohol wipe and let dry.
10. Inject Strensiq in your stomach area, upper arms, or upper legs as directed by your doctor. Do not inject if your skin is red or swollen.

If the volume to be injected is more than 1 mL, it will need to be split into two syringes and injected into two different injection sites. Make sure that you rotate the sites where you are injecting Strensiq.

If you miss a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time. Do not take two doses of Strensiq at the same time.
 

If you take too much Strensiq, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

If Strensiq is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

Do not inject this medicine into skin areas that are red or swollen.

Get emergency medical help if you have signs of an allergic reaction: hives; dizziness, nausea, vomiting; difficult breathing, choking sensation; swelling of your face, lips, tongue, or throat.

Common side effects may include:

• pain, itching, swelling, redness, bruising, hardening, pitting, or other skin changes where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Hypophosphatasia

Enzyme replacement therapy in patients with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP);1 3 4 5 designated an orphan drug by FDA for use in these conditions.2

Improves overall and invasive ventilation-free survival in patients with perinatal/infantile-onset HPP;1 3 5 improvements in growth, radiologic scores, histologic parameters, and biochemical markers also observed in such patients.1 3 4 5

Improves growth, mobility, radiologic scores, histologic parameters, and biochemical markers in patients with juvenile-onset HPP.1 3

HPP registry established to monitor variability and progression of HPP and long-term effects of asfotase alfa.1 Encourage patients and their caregivers to participate in this voluntary program.1 For more information, visit .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.

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)].

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 volume needed for the prescribed dosage based on the patient's weight and recommended dosage. Follow these steps to determine the patient dose.

Total dose (mg) = patient's weight (kg) × prescribed dose (mg/kg)

Total injection volume (mL) = Total dose (mg) divided by concentration (40 mg/mL or 80 mg/0.8 mL)

Round total injection volume to the nearest hundredth of a mL

Total number of vials = Total injection volume divided by vial volume (mL)

2. Determine frequency of weekly injections. 3. Determine dose. 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 (2.1)] (Table 3). 4. 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. Table 1: Weight-Based Dosing for Administration of 2 mg/kg Three Times per Week

Body Weight (kg)*	Dose to Inject	Volume to Inject	Vial Configuration
* 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)]. † 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.
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/mL
20	40 mg	1 mL	40 mg/mL
25	50 mg	1.25 mL	Two 28 mg/0.7 mL vials
30	60 mg	1.5 mL	Two 40 mg/mL vials
35	70 mg	1.75 mL	Two 40 mg/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†	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)*	Dose to Inject	Volume to Inject	Vial Configuration
* 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)].
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/mL
35	35 mg	0.88 mL	40 mg/mL
40	40 mg	1 mL	40 mg/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*

Body Weight (kg)†	Dose to Inject	Volume to Inject	Vial Configuration
* A regimen of 3 mg/kg three times per week is recommended only for patients with perinatal/infantile-onset HPP [see Dosage and Administration (2.1)] † 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)]. ‡ 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.
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/mL
15	45 mg	1.13 mL‡	Two 28 mg/0.7 mL vials
20	60 mg	1.5 mL‡	Two 40 mg/mL vials
25	75 mg	1.88 mL‡	Two 40 mg/mL vials

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; 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. For doses greater than 1 mL, the injection volume should be split equally between two 1 mL syringes. Always use a new syringe and needle. 7. Remove vial cap, aseptically prepare the vial and insert the syringe into the vial to withdraw the prescribed dose for administration. 8. Remove any air bubbles in the syringe and verify the correct dose.

Administration

Strensiq is for subcutaneous injection only.

1. Administer Strensiq within 1 hour upon removal of the vial(s) from refrigeration. 2. Rotate the injection from among the following sites to reduce the risk of lipodystrophy: abdominal area, thigh, or deltoid [see Warnings and Precautions (5.2), Adverse Reactions (6.1)]. 3. Do NOT administer injections in areas that are reddened, inflamed, or swollen. 4. Inject Strensiq subcutaneously into the determined site and properly dispose of the needle. 5. Strensiq vials are single use only. Discard any unused product.

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

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 µmol 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. Table 5 describes the content of Strensiq vial presentations.

Table 5: Content of Strensiq Vial Presentations

Ingredient	Quantity per Vial
Asfotase Alfa	18 mg/0.45 mL	28 mg/0.7 mL	40 mg/mL	80 mg/0.8 mL
Dibasic sodium phosphate, heptahydrate	2.48 mg	3.85 mg	5.5 mg	4.4 mg
Monobasic sodium phosphate, monohydrate	0.28 mg	0.43 mg	0.62 mg	0.5 mg
Sodium chloride	3.94 mg	6.13 mg	8.76 mg	7.01 mg

Perinatal/Infantile-Onset HPP

Study 1 was a 24-week prospective single-arm trial in 11 patients, 7/11 (64%) were female and 10/11 (91%) were white, aged 3 weeks to 39.5 months with severe perinatal/infantile-onset HPP. Severe perinatal/infantile-onset HPP was defined as biochemical, medical history and radiographic evidence of HPP as well as the presence of any of the following: rachitic chest deformity, vitamin B6-dependent seizures, or failure to thrive. Ten of 11 patients completed the 24-week trial and continued treatment in the extension phase. Nine patients have been treated for at least 216 weeks (54 months) and 4 patients have been treated for over 240 weeks (60 months). Patients received Strensiq at 3 mg/kg per week for the first month; subsequently, dose increases up to 9 mg/kg per week were allowed for changes in weight and/or for lack of efficacy. All 10 patients required dose increases of up to 6 mg/kg per week or higher; 9 patients increased between 4 and 24 weeks after starting treatment and 1 patient increased after 70 weeks due to suboptimal clinical response. One patient's dose was decreased from 9 mg/kg per week to 6 mg/kg per week based on PK data.

Study 2 was a prospective open-label study in 59 patients, 32/59 (54%) were female and 46/59 (78%) were white, aged 1 day to 78 months with perinatal/ infantile-onset HPP. Patients received Strensiq at 6 mg/kg per week for the first 4 weeks. Ten patients received dose increases higher than 6 mg/kg per week due to suboptimal clinical response, with dose increases occurring between 8 and 24 weeks after starting treatment. The recommended dosage regimen of Strensiq for the treatment of perinatal/infantile-onset HPP is up to 9 mg/kg per week administered subcutaneously as 3 mg/kg three times per week [see Dosage and Administration (2.1)].

Forty-one patients have been treated for at least 24 weeks (6 months) and 15 patients have been treated for at least 96 weeks (24 months).

Survival and Ventilation-Free Survival

Survival and invasive ventilation-free survival were compared in Strensiq-treated patients (Studies 1 and 2) with a historical cohort of untreated patients with similar clinical characteristics (Table 7 and Figure 1).

Table 7: Survival and Invasive Ventilation-Free Survival in Strensiq-Treated versus Historical Control Patients with Perinatal/ Infantile-Onset HPP

	Strensiq-Treated	Historical Controls
* Adjusted for year of diagnosis. † Alive and not initiating invasive ventilation after start of Strensiq treatment. Strensiq-treated patients on invasive ventilation at baseline were excluded from this analysis.
Survival	n = 68	n = 48
Alive at Point of Last Contact (%)	91	27
Hazard Ratio (Strensiq/Historical Control), 95% Confidence Interval*	0.14 (0.05, 0.39)
Kaplan-Meier Estimate and Alive at Age 1 Year (Week 48) (%)	97	42
Invasive Ventilation-Free Survival†	n = 54	n = 48
Alive and Not on Ventilation at Point of Last Contact (%)	85	25
Hazard Ratio (Strensiq/Historical Control), 95% Confidence Interval*	0.21 (0.09, 0.51)
Kaplan-Meier Estimate of Alive and Not on Ventilation at Age 1 Year (Week 48) (%)	96	31

In patients who required any form of respiratory support, 21 of 26 (81%) of the treated patients survived through their last assessment (median age at last assessment was 3.2 years of age), versus 1 of 20 (5%) of historical controls.

Figure 1: Overall Survival in Strensiq-Treated versus Historical Control Patients with Perinatal/ Infantile-Onset HPP

Skeletal Manifestations

Radiographs from 68 Strensiq-treated perinatal/infantile-onset HPP patients, including 64 patients in Studies 1 and 2, and 4 patients in Study 3 [see Clinical Studies (14.2)], were examined to assess HPP-related rickets using the 7-point Radiographic Global Impression of Change (RGI-C) scale. Patients with a minimum RGI-C score of +2 were defined as "responders". Radiologic improvements could be seen by Month 24; at last assessment, 50/68 [74%] treated patients were rated as RGI-C responders. No comparative data were available from historical controls. The mean time interval between the baseline and last RGI-C assessment was 24 months (range was 1 month to 67 months).

Eighteen perinatal/infantile-onset HPP patients experienced fractures during the course of treatment. There were insufficient data to determine the effect of Strensiq on fractures.

Growth

Height and weight measurements (as measured by z-scores) were available post-treatment for 72 perinatal/infantile-onset HPP patients, including 68 patients enrolled in Studies 1 and 2, and 4 patients enrolled in Study 3 (Table 8).

Table 8: Perinatal/Infantile-Onset Height and Weight Measurements as Measured by Z-Score

	Height Z-score				Weight Z-score
	Baseline		Last Assessment		Baseline		Last Assessment
	Mean	Min, Max	Mean	Min, Max	Mean	Min, Max	Mean	Min, Max
* The mean time interval between baseline and last assessment was 21 months (range was 1 month to 72 months). † The mean time between baseline and last assessment was 56 months (range was 53 months to 60 months).
Studies 1 and 2* (N=68)	-3.3	-10.1, 0.9	-2.9	-10.6, 0.4	-3.2	-23.8, 0	-2.4	-20.9, 1.1
Study 3 (N=4)†	-2.6	-6.6, -0.7	-1.5	-5.8, 0.4	-2.5	-8.2, -1.0	-1.5	-5.4, 0.5

Juvenile-Onset HPP

Study 3 was a prospective open-label 24-week trial that included 8 juvenile-onset HPP patients and 5 perinatal/ infantile-onset HPP patients, 11/13 (85%) were male and 12/13 (92%) were white [see Clinical Studies (14.1)]; on entry, patients were 6 to 12 years of age. All 8 juvenile-onset patients entered the extension study and were treated for at least 48 months. At trial entry, patients were randomized to receive Strensiq at 6 mg/kg per week or 9 mg/kg per week. Two patients received dose reductions during the primary treatment period, including one patient who experienced a decrease in vitamin B6 levels and one patient who experienced recurrent injection site reactions. During the extension phase, the dosing regimen for all patients was initially changed to 3 mg/kg per week. Dosing was subsequently increased to 6 mg/kg per week, with no patients requiring doses higher than 6 mg/kg per week. The recommended dosage regimen of Strensiq for the treatment of juvenile-onset HPP is 6 mg/kg per week [see Dosage and Administration (2.1)].

Growth

Height and weight measurements (as measured by z-scores) in 8 Strensiq-treated patients were compared with a historical cohort of 32 untreated patients with similar clinical characteristics (Table 9). Height and weight data for historical patients were collected from medical records.

Table 9: Juvenile-Onset Height and Weight Measurements as Measured by Z-Score

	Height Z-score				Weight Z-score
	Baseline		Last Assessment		Baseline		Last Assessment
	Mean	Min, Max	Mean	Min, Max	Mean	Min, Max	Mean	Min, Max
* The mean time interval between baseline and last assessment was 55 months (range was 53 months to 60 months). † The mean time interval between baseline and last assessment was 61 months (range was 19 months to 109 months).
Strensiq (N=8)*	-1.5	-3.8, 0	-0.9	-2, 0	-1.1	-3.5, 2.3	0	-1.3, 2.2
Control (N=32)†	-1.1	-4.9, 2.6	-1.1	-4.9, 1.8	-1.2	-5, 2.1	-1	-5.7, 2.1

Skeletal Manifestations

Radiographs from 8 Strensiq-treated patients and 32 historical controls were compared to assess HPP-related rickets using the 7-point RGI-C (Radiographic Global Impression of Change) scale. Patients who achieved a RGI-C score of 2 or higher (corresponding to substantial healing of rickets) were classified as being responders to treatment. All 8 treated patients were rated as responders by Month 54 of treatment. The mean duration between the baseline and last RGI-C assessments for control patients was 56 months (range was 8 to 95 months). At last assessment, 2/32 (6%) of control patients were rated as responders.

Eight of 20 (40%) patients with juvenile-onset HPP experienced new fractures during the course of treatment. There were insufficient data to assess the effect of Strensiq on fractures.

Gait/Mobility

Gait was assessed using a modified Performance Oriented Mobility Assessment-Gait (MPOMA-G) scale in 8 Strensiq-treated patients at 6 month intervals out to 36 months. Mobility was also assessed using the 6 Minute Walk Test (6MWT) in 7 of the 8 patients. Step length improved by at least 1 point in either foot in 6/8 patients compared to 1/6 (17%) control patients. The proportion of patients who had 6MWT percent predicted values within the normal range for age, sex, and height-matched peers increased from 0/8 patients at baseline to 6/6 patients (100%) by Month 48 and all 6 were also able to walk longer distances at this time point compared to baseline.

Strensiq (asfotase alfa) is an enzyme replacement medicine that is used to treat hypophosphatasia (HYE-poe-FOS-fa-TAY-zha).

Hypophosphatasia is a rare genetic disorder in which there is a deficiency of an enzyme that helps the body process calcium and phosphorus. This leads to abnormal growth and development of the bones and teeth, including soft or brittle bones, growth problems, and tooth loss.

Strensiq may also be used for purposes not listed in this medication guide.