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Monoclonal Antibodies

ALXN1850 for Hypophosphatasia (CHESTNUT Trial)

Phase 3

Recruiting

Research Sponsored by Alexion Pharmaceuticals, Inc.

Eligibility Criteria Checklist

Specific guidelines that determine who can or cannot participate in a clinical trial

Must have

Diagnosis of HPP documented in the medical records

Tanner stage 2 or less during the Screening Period

Must not have

Any new fracture within 12 weeks before Day 1 (excluding pseudofractures)

History of allergy or hypersensitivity to any ingredient contained in asfotase alfa or ALXN1850

Timeline

Screening 3 weeks

Treatment Varies

Follow Up up to 5 years

Awards & highlights

Pivotal Trial

No Placebo-Only Group

Summary

This trial will test if a new medication is safe and effective for children with a rare bone disease.

Who is the study for?

This trial is for children with Hypophosphatasia (HPP) who are in early puberty or younger, have open growth plates, and have been treated with asfotase alfa for at least 6 months. They must weigh over 10 kg and not have had a new fracture recently. Kids can't join if they've had certain other health problems or surgeries that might affect the study, or if they're allergic to ingredients in the treatments.

What is being tested?

The trial is testing ALXN1850 against asfotase alfa to see which one is safer and more tolerable for kids with HPP who've already tried asfotase alfa. It's a Phase 3 study where participants will be randomly assigned to receive either ALXN1850 or continue their current treatment of asfotase alfa.

What are the potential side effects?

Possible side effects from ALXN1850 could include reactions similar to those experienced with asfotase alfa since both drugs treat HPP. These may involve issues at the injection site, allergic reactions, or complications related to the conditions being treated.

Eligibility Criteria

Inclusion Criteria

You may be eligible if you check “Yes” for the criteria below

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My medical records show a diagnosis of HPP.

Select...

My physical development is at or before early puberty.

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I have been treated with asfotase alfa for at least 6 months.

Exclusion Criteria

You may be eligible for the trial if you check “No” for criteria below:

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I have not had any new fractures in the last 12 weeks.

Select...

I am not allergic to asfotase alfa or ALXN1850.

Select...

I do not have any major health issues that could affect how my body handles medication.

Select...

My body weight is less than 10 kg.

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I have hypoparathyroidism not caused by HPP.

Select...

I have been diagnosed with hyperparathyroidism.

Timeline

Screening ~ 3 weeks3 visits

Treatment ~ Varies

Follow Up ~ up to 5 years

Screening ~ 3 weeks

Treatment ~ Varies

Follow Up ~up to 5 years

This trial's timeline: 3 weeks for screening, Varies for treatment, and up to 5 years for reporting.

Treatment Details

Awards & Highlights

Pivotal Trial

The final step before approval, pivotal trials feature drugs that have already shown basic safety & efficacy.

No Placebo-Only Group

All patients enrolled in this study will receive some form of active treatment.

Trial Design

2Treatment groups

Experimental Treatment

Group I: asfotase alfaExperimental Treatment1 Intervention

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 II: ALXN1850Experimental Treatment2 Interventions

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.

Treatment

First Studied

Drug Approval Stage

How many patients have taken this drug

ALXN1850

2021

Completed Phase 1

~20

asfotase alfa

2008

Completed Phase 3

~180