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

Hypophosphatasia Clinical Trial

— CHESTNUT  

Official title:

A Phase 3, Randomized, Open-label, Parallel-arm, Active-controlled, Multicenter Study to Evaluate Safety and Efficacy of ALXN1850 Versus Asfotase Alfa Administered Subcutaneously in Pediatric Participants (2 to < 12 Years of Age) With Hypophosphatasia (HPP) Previously Treated With Asfotase Alfa

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06079372
• Other study ID #: D8590C00004
• Secondary ID: ALXN1850-HPP-303
• Status: Recruiting
• Phase: Phase 3
• Start date: April 2, 2024
• Est. completion date: October 15, 2027

Study information

• Verified date: May 2024
• Source: Alexion Pharmaceuticals, Inc.
• Contact: Alexion Pharmaceuticals, Inc. (Sponsor)
• Phone: 1-855-752-2356
• Email: clinicaltrials[@]alexion.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 40
• Est. completion date: October 15, 2027
• Est. primary completion date: April 21, 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 2 Years to 11 Years

Eligibility

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

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

Related Conditions & MeSH terms

• Hypophosphatasia

Intervention

Drug:
• ALXN1850
ALXN1850 will be administered via subcutaneous (SC) injection.
• asfotase alfa
Asfotase alfa will be administered via SC injection.

Locations

Country	Name	City	State
Argentina	Research Site	Buenos Aires
Argentina	Research Site	Córdoba
Argentina	Research Site	Mar del Plata
Argentina	Research Site	Mar del Plata
Australia	Research Site	South Brisbane
Australia	Research Site	Westmead
Canada	Research Site	Ottawa	Ontario
Canada	Research Site	Winnepeg	Manitoba
France	Research Site	Le Kremlin Bicêtre
France	Research Site	Paris
Germany	Research Site	Homburg
Germany	Research Site	Würzburg
India	Research Site	Bangalore
Italy	Research Site	Genova
Italy	Research Site	Milano
Italy	Research Site	Roma
Japan	Research Site	Bunkyo-ku
Japan	Research Site	Kyoto-shi
Japan	Research Site	Minato-ku
Japan	Research Site	Suita-shi
Turkey	Research Site	Ankara
Turkey	Research Site	Ankara
Turkey	Research Site	Bursa
Turkey	Research Site	Edirne
Turkey	Research Site	Erzurum
Turkey	Research Site	Istambul
Turkey	Research Site	Küçükçekmece
United Kingdom	Research Site	Birmingham
United Kingdom	Research Site	Manchester
United Kingdom	Research Site	Sheffield
United States	Research Site	Baltimore	Maryland
United States	Research Site	Boston	Massachusetts
United States	Research Site	Durham	North Carolina
United States	Research Site	Hartford	Connecticut
United States	Research Site	Kansas City	Missouri
United States	Research Site	Minneapolis	Minnesota
United States	Research Site	Nashville	Tennessee
United States	Research Site	Saint Louis	Missouri

Sponsors (1)

Lead Sponsor	Collaborator
Alexion Pharmaceuticals, Inc.

Countries where clinical trial is conducted

United States,  Argentina,  Australia,  Canada,  France,  Germany,  India,  Italy,  Japan,  Turkey,  United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Number of Participants with Treatment-emergent Adverse Events (TEAEs)		Baseline Through Day 169
Secondary	Radiographic Global Impression of Change (RGI-C) Score at the end of the Randomized Evaluation Period (Day 169)		Baseline, Day 169
Secondary	Change from Baseline in Rickets Severity Score (RSS) at the end of the Randomized Evaluation Period (Day 169)		Baseline, Day 169
Secondary	Change from Baseline in 6-Minute Walk Test (6MWT) at the end of the Randomized Evaluation Period (Day 169)		Baseline, Day 169
Secondary	Change from Baseline in Percent Predicted 6MWT at the end of the Randomized Evaluation Period (Day 169)		Baseline, Day 169
Secondary	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
Secondary	Change from Baseline in Peabody Developmental Motor Scales, Third Edition (PDMS-3) Score at the end of the Randomized Evaluation Period (Day 169)		Baseline, Day 169