NCT06079372

Brief Summary

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.

Trial Health

82
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
43

participants targeted

Target at below P25 for phase_3

Timeline
22mo left

Started Apr 2024

Typical duration for phase_3

Geographic Reach
7 countries

21 active sites

Status
active not recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress54%
Apr 2024Feb 2028

First Submitted

Initial submission to the registry

October 6, 2023

Completed
6 days until next milestone

First Posted

Study publicly available on registry

October 12, 2023

Completed
6 months until next milestone

Study Start

First participant enrolled

April 2, 2024

Completed
1.3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

July 23, 2025

Completed
2.6 years until next milestone

Study Completion

Last participant's last visit for all outcomes

February 29, 2028

Expected
Last Updated

May 5, 2026

Status Verified

May 1, 2026

Enrollment Period

1.3 years

First QC Date

October 6, 2023

Last Update Submit

May 1, 2026

Conditions

Hypophosphatasia

Keywords

HypophosphatasiaHPPAsfotase AlfaALXN1850

Outcome Measures

Primary Outcomes (1)

  • Number of Participants with Treatment-emergent Adverse Events (TEAEs)

    Baseline Through Day 169

Secondary Outcomes (6)

  • Radiographic Global Impression of Change (RGI-C) Score at the end of the Randomized Evaluation Period (Day 169)

    Baseline, Day 169

  • Change from Baseline in Rickets Severity Score (RSS) at the end of the Randomized Evaluation Period (Day 169)

    Baseline, Day 169

  • Change from Baseline in 6-Minute Walk Test (6MWT) at the end of the Randomized Evaluation Period (Day 169)

    Baseline, Day 169

  • Change from Baseline in Percent Predicted 6MWT at the end of the Randomized Evaluation Period (Day 169)

    Baseline, Day 169

  • Change from Baseline in Bruininks Oseretsky Test of Motor Proficiency, Second Edition (BOT2) Score at the end of the Randomized Evaluation Period (Day 169)

    Baseline, Day 169

  • +1 more secondary outcomes

Study Arms (2)

ALXN1850

EXPERIMENTAL

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.

Drug: ALXN1850Drug: asfotase alfa

asfotase alfa

EXPERIMENTAL

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.

Drug: asfotase alfa

Interventions

ALXN1850DRUG

ALXN1850 will be administered via subcutaneous (SC) injection.

ALXN1850
asfotase alfaDRUG

Asfotase alfa will be administered via SC injection.

ALXN1850asfotase alfa

Eligibility Criteria

Age2 Years - 11 Years
Sexall
Healthy VolunteersNo
Age GroupsChild (0-17)

You may qualify if:

  • 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.

You may not qualify if:

  • 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

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (21)

Research Site

Hartford, Connecticut, 06106, United States

Location

Research Site

Baltimore, Maryland, 21287, United States

Location

Research Site

Minneapolis, Minnesota, 55455, United States

Location

Research Site

Kansas City, Missouri, 64108, United States

Location

Research Site

Durham, North Carolina, 27705, United States

Location

Research Site

Nashville, Tennessee, 37212, United States

Location

Research Site

Mar del Plata, B7600, Argentina

Location

Research Site

South Brisbane, 4101, Australia

Location

Research Site

Ottawa, Ontario, K1H 8L1, Canada

Location

Research Site

Bunkyō City, 113-8431, Japan

Location

Research Site

Minatoku, 105-8471, Japan

Location

Research Site

Suita-shi, 565-0871, Japan

Location

Research Site

Yonago-shi, 683-8504, Japan

Location

Research Site

Altındağ, 06230, Turkey (Türkiye)

Location

Research Site

Ankara, 06560, Turkey (Türkiye)

Location

Research Site

Edirne, 22030, Turkey (Türkiye)

Location

Research Site

Erzurum, 25240, Turkey (Türkiye)

Location

Research Site

Istanbul, 34899, Turkey (Türkiye)

Location

Research Site

Birmingham, B4 6NH, United Kingdom

Location

Research Site

Manchester, United Kingdom

Location

Research Site

Sheffield, S10 2TH, United Kingdom

Location

MeSH Terms

Conditions

Hypophosphatasia

Interventions

asfotase alfa

Condition Hierarchy (Ancestors)

Metal Metabolism, Inborn ErrorsMetabolism, Inborn ErrorsGenetic Diseases, InbornCongenital, Hereditary, and Neonatal Diseases and AbnormalitiesMetabolic DiseasesNutritional and Metabolic Diseases

Study Design

Study Type
interventional
Phase
phase 3
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
INDUSTRY
Responsible Party
SPONSOR

Study Record Dates

First Submitted

October 6, 2023

First Posted

October 12, 2023

Study Start

April 2, 2024

Primary Completion

July 23, 2025

Study Completion (Estimated)

February 29, 2028

Last Updated

May 5, 2026

Record last verified: 2026-05

Data Sharing

IPD Sharing
Will share

Alexion has a public commitment to allow requests for access to study data and will be supplying a protocol, CSR, and plain language summaries.

Shared Documents
STUDY PROTOCOL, SAP, CSR

Locations

TU(5)AR(1)CA(1)JP(4)AU(1)GB(3)US(6)