Phase 3 Study of ALXN1850 in Treatment-Naïve Pediatric Participants With HPP

Inclusion criteria

• ✓. Presence of HPP-related rickets on skeletal X-rays during the Screening Period, with a minimum Rickets Severity Score (RSS) of 1.0 AND
• ✓. Serum ALP activity below the age- and sex-adjusted normal range during the Screening Period as measured by the Central Laboratory OR 2 documented serum ALP activity results, at least 15 days apart, below the age- and sex-adjusted local laboratory normal range during the 24 months before the Day 1 Visit. Note: Local laboratories need to be Clinical Laboratory Improvement Amendments (CLIA) or ISO 15189 certified, or have other local equivalent laboratory certification with Alexion's approval.
• ✓. Documented ALPL gene variant (pathogenic, likely pathogenic, or variant of unknown significance) from a CLIA certified laboratory (Section 8.7)
• ✓. Plasma PLP above the upper limit of normal (ULN) during the Screening Period (central or local laboratory results allowed per local regulations)