A Prospective Sub-Study of the Global Hypophosphatasia Registry

In this prospective observational sub-study, participants with pediatric-onset hypophosphatasia (HPP) (perinatal/infantile- or juvenile-onset) of any age will be followed for a minimum of 5 years at sites in the United States and potentially 1 or 2 other countries.

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Key information

Conditions

Hypophosphatasia Congenital, Hereditary, and Neonatal Diseases and Abnormalities Genetic Diseases, Inborn Metabolic Diseases Metabolism, Inborn Errors Metal Metabolism, Inborn Errors Nutritional and Metabolic Diseases

Sex eligibility

All sexes

Study type

Observational

Primary location

Clinical Trial Site, Hartford, Connecticut, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Any age or sex with a confirmed diagnosis of pediatric-onset HPP (that is, first HPP sign or symptom presented at < 18 years of age).
Currently receiving asfotase alfa treatment at Enrollment (not treatment-naïve) or the Physician has decided to resume (not treatment-naïve) or start (treatment-naïve) the participant's asfotase alfa treatment within 6 months after Enrollment.
Participant must have documented alkaline phosphatase (ALP) activity below the lower limit of normal for age and sex, and a documented ALPL gene mutation (Note: An exception is made for infants with clinical features of HPP plus low ALP who need to start asfotase alfa treatment right away, at the Physician's discretion, but do not yet have a genetic result. In this case, ALPL gene documentation is not required at the time of sub-study enrollment but should be documented within 6 months after Enrollment).
Participant or participant's parent/legally authorized representative is able to read and/or understand the informed consent and study questionnaires in the local language.
Participant or participant's parent/legally authorized representative must be willing and able to give signed informed consent for this sub-study, and the participant must be willing to give written informed assent, if appropriate and required by local regulations.

Exclusion criteria

Currently participating in an Alexion-sponsored interventional clinical study. Participants who have concluded participation in an Alexion-sponsored asfotase alfa clinical study are eligible to enroll in this sub-study.

Treatment and study plan

Asfotase Alfa

Biological

All participants will receive asfotase alfa subcutaneously per standard of care. Unless otherwise specified per the Physician's standard of care, participants aged < 2 years are recommended for a clinic visit approximately every 3 months after Enrollment until 2 years of age, after which they should have a clinic visit approximately every 6 months. Participants should be followed for 5 years, as possible.

Other names: Strensiq

Primary outcomes

Occurrence Of Immune-mediated Loss Of Effectiveness According To The Treating Physician

Time frame: Up to 5 years

This will be based on clinical and biochemical assessments as well as positive anti-drug antibodies and positive neutralizing antibodies.
Occurrence Of Immune-mediated Serious Adverse Events

Time frame: Up to 5 years

These serious adverse events will include serious hypersensitivity reactions and anaphylaxis.

Study contacts

Contact information is provided by the study sponsor or research team.

Alexion Pharmaceuticals, Inc. (Sponsor)

CONTACT

[email protected]

1-855-752-2356

Sponsors and collaborators

Lead sponsor

Alexion Pharmaceuticals, Inc.

Industry

Registry information

Official study title

A Prospective Observational Sub-Study of the Global Hypophosphatasia Registry to Describe the Potential Risk of Immune-Mediated Loss of Pharmacological Effect of Asfotase Alfa in Participants With Hypophosphatasia

Important dates

Study start: 2022
Primary completion: 2028
Study completion: 2028
First posted: Feb 10, 2022
Registry last updated: Feb 9, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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