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

JRCT ID: jRCT2051230131

Registered date:19/11/2023

Basic Information

• Recruitment status: Recruiting
• Health condition(s) or Problem(s) studied: Hypophosphatasia
• Date of first enrollment: 02/04/2024
• Target sample size: 4
• Countries of recruitment: Argentina,Japan,Australia,Japan,Canada,Japan,France,Japan,Germany,Japan,Italy,Japan,Turkey,Japan,United Kingdom,Japan,United States of America,Japan
• Study type: Interventional

Intervention(s)

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.

Outcome(s)

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

Key inclusion & exclusion criteria

• Age minimum: >= 2age old
• Age maximum: < 12age old
• Gender: Both

Include criteria

1. Participant must be 2 or more and < 12 years of age at Day 1.
2. Diagnosis of HPP documented in the medical records
3. Presence of open growth plates by X-ray during Screening Period
4. Tanner stage 2 or less during the Screening Period
5. 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 more than 6 months before Day 1

Exclude criteria

1. 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.
2. Diagnosis of primary or secondary hyperparathyroidism
3. Hypoparathyroidism, unless secondary to HPP
4. Any new fracture within 12 weeks before Day 1 (excluding pseudofractures)
5. Planned surgical intervention which may impact the results of study assessments (in the opinion of the Investigator) during the Randomized Evaluation Period
6. History of allergy or hypersensitivity to any ingredient contained in asfotase alfa or ALXN1850
7. Body weight < 10 kg during the Screening Period

Related Information

• Primary Sponsor: Wuebbenhorst Hiroaki
• Secondary ID(s): NCT06079372