Phase 3 Study of ALXN1850 in Pediatric Participants With HPP Previously Treated With Asfotase Alfa

NCT ID: NCT06079372

Last Updated: 2025-11-13

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

ACTIVE_NOT_RECRUITING

Clinical Phase

PHASE3

Total Enrollment

43 participants

Study Classification

INTERVENTIONAL

Study Start Date

2024-04-02

Study Completion Date

2028-02-29

Brief Summary

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The primary purpose of this study is to assess the safety and tolerability of ALXN1850 versus asfotase alfa in pediatric participants with HPP previously treated with asfotase alfa.

Detailed Description

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Conditions

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Hypophosphatasia

Keywords

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Hypophosphatasia HPP Asfotase Alfa ALXN1850

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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ALXN1850

Starting at Day 1 of the Randomized Evaluation Period participants will receive ALXN1850 for a total of 24 weeks. Participants will receive bodyweight dependent doses of either 20mg, 35mg or 50mg of ALXN1850 once q2w via SC injection. During Part A of the OLE Period, participants will have frequent visits over the first 24 weeks; Part B of the OLE Period participants will have visits every 9 months for up to approximately 108 weeks.

Group Type EXPERIMENTAL

ALXN1850

Intervention Type DRUG

ALXN1850 will be administered via subcutaneous (SC) injection.

asfotase alfa

Intervention Type DRUG

Asfotase alfa will be administered via SC injection.

asfotase alfa

Starting at Day 1 of the Randomized Evaluation Period, participants will receive asfotase alfa for a total of 24 weeks. Participants will receive 6 mg/kg/week of asfotase alfa via SC injection as either 2 mg/kg 3 times per week or 1 mg/kg 6 times per week. Part A of the OLE Period participants will have frequent visits over the first 24 weeks; Part B will have visits every 9 months for up to approximately 108 weeks.

Group Type EXPERIMENTAL

asfotase alfa

Intervention Type DRUG

Asfotase alfa will be administered via SC injection.

Interventions

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ALXN1850

ALXN1850 will be administered via subcutaneous (SC) injection.

Intervention Type DRUG

asfotase alfa

Asfotase alfa will be administered via SC injection.

Intervention Type DRUG

Eligibility Criteria

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Inclusion Criteria

* Diagnosis of HPP documented in the medical records
* Presence of open growth plates by X-ray during Screening Period
* Tanner stage 2 or less during the Screening Period
* Must have been treated with 6 mg/kg/ week of asfotase alfa via SC injection administered as either 2mg/kg 3 times per week or 1 mg/kg 6 times per week for ≥ 6 months before Day 1. Note: participants currently treated with 9 mg/kg (eg, 3 mg/kg 3 times per week) will not be allowed in the study.

Exclusion Criteria

* History or presence of cardiovascular, respiratory, hepatic, renal, gastrointestinal, endocrinological, hematological, neurological disorders, or any other disorders that are capable of significantly altering the absorption, metabolism, or elimination of drugs; constituting a risk when taking the study intervention; or interfering with the interpretation of data as determined by the Investigator.
* Diagnosis of primary or secondary hyperparathyroidism
* Hypoparathyroidism, unless secondary to HPP
* Any new fracture within 12 weeks before Day 1 (excluding pseudofractures)
* Planned surgical intervention which may impact the results of study assessments (in the opinion of the Investigator) during the Randomized Evaluation Period
* History of allergy or hypersensitivity to any ingredient contained in asfotase alfa or ALXN1850
* Body weight \< 10 kg during the Screening Period
Minimum Eligible Age

2 Years

Maximum Eligible Age

11 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Alexion Pharmaceuticals, Inc.

INDUSTRY

Sponsor Role lead

Responsible Party

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Responsibility Role SPONSOR

Locations

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Research Site

Hartford, Connecticut, United States

Site Status

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Baltimore, Maryland, United States

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Minneapolis, Minnesota, United States

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Kansas City, Missouri, United States

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Durham, North Carolina, United States

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Nashville, Tennessee, United States

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Mar del Plata, , Argentina

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South Brisbane, , Australia

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Ottawa, Ontario, Canada

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Bunkyō City, , Japan

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Minatoku, , Japan

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Suita-shi, , Japan

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Yonago-shi, , Japan

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Altındağ, , Turkey (Türkiye)

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Ankara, , Turkey (Türkiye)

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Edirne, , Turkey (Türkiye)

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Erzurum, , Turkey (Türkiye)

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Istanbul, , Turkey (Türkiye)

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Birmingham, , United Kingdom

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Manchester, , United Kingdom

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Sheffield, , United Kingdom

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Countries

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France Germany India Italy United States Argentina Australia Canada Japan Turkey (Türkiye) United Kingdom

Other Identifiers

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ALXN1850-HPP-303

Identifier Type: OTHER

Identifier Source: secondary_id

D8590C00004

Identifier Type: -

Identifier Source: org_study_id