A Prospective Sub-Study of the Global Hypophosphatasia Registry

NCT05234567 | Recruiting FDA Drug

• 1 other identifier: ALX-HPP-501s
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 12

Brief Summary

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.

Conditions

Hypophosphatasia

Keywords

Pediatric Onset; HPP; Asfotase alfa

Outcome Measures

Primary Outcomes (2)

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

  This will be based on clinical and biochemical assessments as well as positive anti-drug antibodies and positive neutralizing antibodies.

  Up to 5 years

• Occurrence Of Immune-mediated Serious Adverse Events

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

  Up to 5 years

Study Arms (1)

Participants with Pediatric-onset HPP

Each participant will be followed for a minimum of 5 years or, if applicable, until early withdrawal. Biochemical, clinical, imaging (if clinically indicated), and functional/quality of life outcomes relevant to HPP will be assessed.

Biological: Asfotase Alfa

Interventions

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.

Also known as: Strensiq

Participants with Pediatric-onset HPP

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Patients with HPP

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Alexion Pharmaceuticals, Inc.: lead

Study Sites (12)

Clinical Trial Site

Hartford, Connecticut, 06106, United States

RECRUITING

Clinical Trial Site

Chicago, Illinois, 60611, United States

RECRUITING

Clinical Trial Site

Boston, Massachusetts, 02122, United States

RECRUITING

Clinical Trial Site

Kansas City, Missouri, 64108, United States

RECRUITING

Clinical Trial Site

Mineola, New York, 11501, United States

RECRUITING

Clinical Trial Site

Cincinnati, Ohio, 45229, United States

NOT YET RECRUITING

Clinical Trial Site

Columbus, Ohio, 43203, United States

RECRUITING

Clinical Trial Site

Pittsburgh, Pennsylvania, 15224, United States

NOT YET RECRUITING

Clinical Trial Site

Nashville, Tennessee, 37112, United States

RECRUITING

Clinical Trial Site

Salt Lake City, Utah, 84108, United States

RECRUITING

Clinical Trial Site

Charlottesville, Virginia, 22903, United States

RECRUITING

Clinical Trial Site

Madison, Wisconsin, 53792, United States

RECRUITING

MeSH Terms

Conditions

Hypophosphatasia

Interventions

asfotase alfa

Condition Hierarchy (Ancestors)

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

Central Study Contacts

Alexion Pharmaceuticals, Inc. (Sponsor)

CONTACT

1-855-752-2356; clinicaltrials@alexion.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 1, 2022
• First Posted: February 10, 2022
• Study Start: August 25, 2022
• Primary Completion (Estimated): July 18, 2028
• Study Completion (Estimated): July 18, 2028
• Last Updated: February 9, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, CSR
• Access Criteria: Alexion will consider requests for disclosure of clinical study participant-level data provided that participant privacy is assured through methods like data de-identification, pseudonymization, or anonymization (as required by applicable law), and if such disclosure was included in the relevant study informed consent form or similar documentation. Qualified academic investigators may request participant-level clinical data and supporting documents (statistical analysis plan and protocol) pertaining to Alexion-sponsored studies. Further details regarding data availability and instructions for requesting information are available in the Alexion Clinical Trials Disclosure and Transparency Policy at https://alexion.com/our-research/research-and-development.

Locations

US (12)