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Trial details imported from ClinicalTrials.gov

For full trial details, please see the original record at https://clinicaltrials.gov/ct2/show/NCT06079372




Registration number
NCT06079372
Ethics application status
Date submitted
6/10/2023
Date registered
12/10/2023
Date last updated
24/05/2024

Titles & IDs
Public title
Phase 3 Study of ALXN1850 in Pediatric Participants With HPP Previously Treated With Asfotase Alfa
Scientific 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
Secondary ID [1] 0 0
ALXN1850-HPP-303
Secondary ID [2] 0 0
D8590C00004
Universal Trial Number (UTN)
Trial acronym
CHESTNUT
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Hypophosphatasia 0 0
Condition category
Condition code

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Treatment: Drugs - ALXN1850
Treatment: Drugs - asfotase alfa

Experimental: 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.

Experimental: 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.


Treatment: Drugs: ALXN1850
ALXN1850 will be administered via subcutaneous (SC) injection.

Treatment: Drugs: asfotase alfa
Asfotase alfa will be administered via SC injection.
Intervention code [1] 0 0
Treatment: Drugs
Comparator / control treatment
Control group

Outcomes
Primary outcome [1] 0 0
Number of Participants with Treatment-emergent Adverse Events (TEAEs)
Timepoint [1] 0 0
Baseline Through Day 169
Secondary outcome [1] 0 0
Radiographic Global Impression of Change (RGI-C) Score at the end of the Randomized Evaluation Period (Day 169)
Timepoint [1] 0 0
Baseline, Day 169
Secondary outcome [2] 0 0
Change from Baseline in Rickets Severity Score (RSS) at the end of the Randomized Evaluation Period (Day 169)
Timepoint [2] 0 0
Baseline, Day 169
Secondary outcome [3] 0 0
Change from Baseline in 6-Minute Walk Test (6MWT) at the end of the Randomized Evaluation Period (Day 169)
Timepoint [3] 0 0
Baseline, Day 169
Secondary outcome [4] 0 0
Change from Baseline in Percent Predicted 6MWT at the end of the Randomized Evaluation Period (Day 169)
Timepoint [4] 0 0
Baseline, Day 169
Secondary outcome [5] 0 0
Change from Baseline in Bruininks Oseretsky Test of Motor Proficiency, Second Edition (BOT2) Score at the end of the Randomized Evaluation Period (Day 169)
Timepoint [5] 0 0
Baseline, Day 169
Secondary outcome [6] 0 0
Change from Baseline in Peabody Developmental Motor Scales, Third Edition (PDMS-3) Score at the end of the Randomized Evaluation Period (Day 169)
Timepoint [6] 0 0
Baseline, Day 169

Eligibility
Key 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
Minimum age
2 Years
Maximum age
11 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key 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

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Parallel
Other design features
Phase
Phase 3
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Recruiting
Data analysis
Reason for early stopping/withdrawal
Other reasons
Date of first participant enrolment
Anticipated
Actual
2/04/2024
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
15/10/2027
Actual
Sample size
Target
40
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 0 0
Research Site - South Brisbane
Recruitment hospital [2] 0 0
Research Site - Westmead
Recruitment postcode(s) [1] 0 0
4101 - South Brisbane
Recruitment postcode(s) [2] 0 0
2145 - Westmead
Recruitment outside Australia
Country [1] 0 0
United States of America
State/province [1] 0 0
Connecticut
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United States of America
State/province [2] 0 0
Maryland
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United States of America
State/province [3] 0 0
Massachusetts
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United States of America
State/province [4] 0 0
Minnesota
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United States of America
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Missouri
Country [6] 0 0
United States of America
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North Carolina
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United States of America
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Tennessee
Country [8] 0 0
Argentina
State/province [8] 0 0
Buenos Aires
Country [9] 0 0
Argentina
State/province [9] 0 0
Córdoba
Country [10] 0 0
Argentina
State/province [10] 0 0
Mar del Plata
Country [11] 0 0
Canada
State/province [11] 0 0
Manitoba
Country [12] 0 0
Canada
State/province [12] 0 0
Ontario
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France
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Le Kremlin Bicêtre
Country [14] 0 0
France
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Paris
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Germany
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Homburg
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Germany
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Würzburg
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India
State/province [17] 0 0
Bangalore
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Italy
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Genova
Country [19] 0 0
Italy
State/province [19] 0 0
Milano
Country [20] 0 0
Italy
State/province [20] 0 0
Roma
Country [21] 0 0
Japan
State/province [21] 0 0
Bunkyo-ku
Country [22] 0 0
Japan
State/province [22] 0 0
Kyoto-shi
Country [23] 0 0
Japan
State/province [23] 0 0
Minato-ku
Country [24] 0 0
Japan
State/province [24] 0 0
Suita-shi
Country [25] 0 0
Turkey
State/province [25] 0 0
Ankara
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Turkey
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Bursa
Country [27] 0 0
Turkey
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Edirne
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Turkey
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Erzurum
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Turkey
State/province [29] 0 0
Istambul
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Turkey
State/province [30] 0 0
Küçükçekmece
Country [31] 0 0
United Kingdom
State/province [31] 0 0
Birmingham
Country [32] 0 0
United Kingdom
State/province [32] 0 0
Manchester
Country [33] 0 0
United Kingdom
State/province [33] 0 0
Sheffield

Funding & Sponsors
Primary sponsor type
Commercial sector/Industry
Name
Alexion Pharmaceuticals, Inc.
Address
Country

Ethics approval
Ethics application status

Summary
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 website
https://clinicaltrials.gov/ct2/show/NCT06079372
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 0 0
Address 0 0
Country 0 0
Phone 0 0
Fax 0 0
Email 0 0
Contact person for public queries
Name 0 0
Alexion Pharmaceuticals, Inc. (Sponsor)
Address 0 0
Country 0 0
Phone 0 0
1-855-752-2356
Fax 0 0
Email 0 0
clinicaltrials@alexion.com
Contact person for scientific queries



Summary Results

For IPD and results data, please see https://clinicaltrials.gov/ct2/show/NCT06079372