Open-Label Study of Asfotase Alfa in Infants and Children ≤ 5 Years of Age With Hypophosphatasia (HPP)

Inclusion Criteria

• •Patients must meet all of the following criteria for enrollment in this study:
• •1. Parent or legal guardian(s) must provide written informed consent prior to any study procedures being performed and must be willing to comply with all study-required procedures. Where appropriate and required by local regulations, patient assent should also be provided prior to any study procedures being performed.
• •2. Documented diagnosis of HPP as indicated by:
• •1. Total serum alkaline phosphatase (ALP) below the lower limit of normal for age NOTE: Historical values for ALP may be used to determine patient eligibility.
• •2. Plasma pyridoxal-5'-phosphate (PLP) above the upper limit of normal (unless patient is receiving pyridoxine for seizures) NOTE: Historical values for PLP may be used to determine patient eligibility.
• •3. Radiographic evidence of HPP at screening, characterized by:
• •* Flared and frayed metaphyses, and
• •* Severe, generalized osteopenia, and
• •* Widened growth plates, and
• •* Areas of radiolucency or sclerosis
• •4. Two or more of the following HPP-related findings:
• •* History or presence of: i) Nontraumatic post-natal fracture or ii) Delayed fracture healing
• •* Nephrocalcinosis or history of elevated serum calcium
• •* Functional craniosynostosis
• •* Respiratory compromise or rachitic chest deformity
• •* Vitamin B6-responsive seizures
• •* Failure to thrive
• •3. Onset of symptoms prior to 6 months of age
• •4. Chronological age or adjusted age for premature infants born ≤ 37 weeks gestation of ≤ 5 years
• •5. Otherwise medically stable in the opinion of the Investigator and/or Sponsor