Prescription medicine
Asfotase alfa Brand names: Strensiq
Asfotase alfa (Strensiq) is a prescription medicine with an FDA approval on record since 2015. No generic is listed in FDA's NDC Directory.
- No generic listed
- Boxed warning
Check it at the source: the asfotase alfa FDA label on DailyMed (effective December 12, 2025, Alexion Pharmaceuticals, Inc.); the BLA 125513 record on Drugs@FDA; every asfotase alfa label on DailyMed.
Highlights of the record
FDA label of December 12, 2025; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026
HYPERSENSITIVITY REACTIONS INCLUDING ANAPHYLAXIS.
Patients treated with enzyme replacement therapies have experienced life-threatening hypersensitivity reactions, including anaphylaxis. 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. Inform patients of the symptoms of life-threatening hypersensitivity reactions, including anaphylaxis and to seek immediate medical care should symptoms occur [see Warnings and Precautions (5.1) ]. WARNING: HYPERSENSITIVITY REACTIONS INCLUDING ANAPHYLAXIS See full prescribing information for complete boxed warning. Anaphylaxis has occurred during the early course of enzyme replacement therapy and after extended duration of therapy. ( 5.1 ) Initiate STRENSIQ under the supervision of a healthcare provider with appropriate medical monitoring and support measures. ( 5.1 ) If a severe hypersensitivity reaction (e.g., anaphylaxis) occurs, discontinue STRENSIQ and immediately initiate appropriate medical treatment, including use of epinephrine.
Used for
From the label: indications and usageSTRENSIQ ® is indicated for the treatment of patients with perinatal/infantile- and juvenile-onset hypophosphatasia (HPP).
Forms and strengths
- 18 mg/.45ml
- 28 mg/.7ml
- 40 mg/ml
- 80 mg/.8ml
Solution.
On the market
- Earliest approval on file
- October 23, 2015 Strensiq, Alexion Pharm; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- No generic approved
- Labelers listed (NDC)
- 1 of which 0 under generic applications, 1 under brand applications, repackagers included
Supply and safety
- Pharmacy cost (NADAC)
- Not in the survey
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
- FAERS reports
- 9,959 through July 30, 2026
What is asfotase alfa used for?
From the label: indications and usageSTRENSIQ ® 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).
FDA pharmacologic class: Tissue-nonspecific Alkaline Phosphatase.
Source: FDA drug label (STRENSIQ), Alexion Pharmaceuticals, Inc., effective December 12, 2025 (SPL set 3387574f-5eaa-4501-a71d-4cbfbd563031), via openFDA; the full label on DailyMed
What does the patient leaflet for asfotase alfa say first?
The FDA-approved Medication Guide or Patient Information that comes with the medicine, in its own words.
From the patient leaflet: What is the most important information I should know about STRENSIQ?STRENSIQ may cause serious side effects, including: severe allergic (hypersensitivity) reactions. Allergic reactions are common with STRENSIQ treatment and can be severe and life-threatening. Severe allergic reactions have happened in some people within minutes after receiving STRENSIQ and more than 1 year after starting treatment with STRENSIQ. Stop using STRENSIQ and go to the nearest hospital emergency room right away if you get any of the following signs and symptoms of a serious allergic reaction: difficulty breathing choking sensation swelling of your eyes, lips, or tongue dizziness nausea or vomiting fever headache sweating feeling irritable chills skin redness skin rash or hives itching or numbness of the tongue, lips, cheeks, or gums
Source: FDA drug label (STRENSIQ), Alexion Pharmaceuticals, Inc., effective December 12, 2025 (SPL set 3387574f-5eaa-4501-a71d-4cbfbd563031), via openFDA; the full label on DailyMed
Is there a generic for asfotase alfa (Strensiq)?
No generic asfotase alfa is approved (Drugs@FDA, October 8, 2026).
- 2015 earliest approval on file
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What does the asfotase alfa label say about other medicines?
The asfotase alfa label names 1 other medicine in its interaction, contraindication or warning sections. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Epinephrine | boxed warning | … anaphylaxis) occurs, discontinue STRENSIQ and immediately initiate appropriate medical treatment, including use of epinephrine. |
Source: FDA drug label (STRENSIQ), Alexion Pharmaceuticals, Inc., effective December 12, 2025 (SPL set 3387574f-5eaa-4501-a71d-4cbfbd563031), via openFDA; the full label on DailyMed
What do FAERS reports show for asfotase alfa?
The FDA Adverse Event Reporting System holds 9,959 reports that list asfotase alfa among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 72 are coded as a death and 752 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Reports rose sharply in 2024 (2,432, against a median of 785 a year): FAERS counts follow reporting, which news, litigation and label changes can drive, not how often a reaction happens.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What next?
- Asfotase alfa side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other