Phase 3 Study of ALXN1850 Versus Placebo in Adolescent and Adult Participants With HPP Who Have Not Previously Been Treated With Asfotase Alfa

• Status: Recruiting
• Trial end date: 2027-08-31
• Target enrollment: 0
• Participant gender: All

Summary

The primary objective of this study is to assess the efficacy of ALXN1850 versus placebo on functional outcomes in adolescent and adult participants with HPP who have not previously been treated with asfotase alfa.

• Phase: Phase 3
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Alexion Pharmaceuticals, Inc.

Criteria

Inclusion Criteria:

• Diagnosis of HPP documented in the medical records

• Must meet 1 of the following criteria:

1. Documented ALPL gene variant (pathogenic, likely pathogenic, or variant of unknown significance) from a Clinical Laboratory Improvement Amendments (CLIA) certified laboratory (Section 8.7 )

2. Plasma PLP above the upper limit of normal (ULN) during the Screening Period (central or local laboratory results allowed per local regulations)

• Serum ALP activity below the age- and sex-adjusted normal range during the screening period, without a probable cause other than HPP

• Two separate 6MWTs at below 85% of the predicted distance (for age, sex, weight, and height) during the Screening Period without a probable cause other than HPP

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 ALXN1850 or the placebo comparator (Table 9)