Participants will be randomized 1:1 to receive either setrusumab or IV-BP. Following randomization, participants will receive setrusumab or IV-BP for up to 24 months during the Active-controlled Period. At the end of the Active-controlled Period all participants will enter the Extension Period and participants assigned to IV-BP will transition to setrusumab. During the Extension Period, all participants will receive setrusumab for a minimum of 12 months or until setrusumab becomes commercially available in their respective country or the study is discontinued. The use of any bisphosphonate is prohibited throughout the Extension Period.
The primary objective of the study is to evaluate the effect of setrusumab vs intravenous bisphosphonates (IV-BP) on reduction in fracture rate, including morphometric vertebral fractures in pediatric participants.