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

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