The primary objective of this study is to evaluate the effect of romosozumab treatment for 12-months compared with bisphosphonate(s) on the number of clinical fractures at 12-months; the number of any fractures at 12-months and change in lumbar spine bone mineral density (BMD) Z-score at 6-months.

Inclusion Criteria:

• Participant has provided informed consent/assent prior to initiation of any study specific activities/procedures.

OR

• Participant's legally authorized representative has provided informed consent when the participant is legally too young to provide informed consent and the participant has provided written assent based on local regulations and/or guidelines prior to any study-specific activities/procedures being initiated.

• Ambulatory male and female children and adolescents, age 5 to <18 years, including ambulatory with assistance as defined in the pediatric osteogenesis imperfecta (OI) population.

• Clinical diagnosis of OI, defined as clinical history consistent with type I, III, or IV OI as determined by presence of expected phenotype (examples include: facial shape, voice, blue sclera, dentinogenesis imperfecta, typical radiographic features, fracture pattern) and lack of additional features unrelated to type I, III, or IV OI (eg, blindness, mental retardation, neuropathy, and craniosynostosis).

  o If familial, also must be autosomal dominant.

• Meets at least one of the following:

  • 3 or more fractures within the previous 2 years, or
  • 1 or more nonvertebral fracture(s) within the previous 2 years and at least 1 prevalent vertebral fracture, or
  • 2 or more prevalent vertebral fractures.

Exclusion Criteria:

Disease Related

• History of an electrophoresis pattern inconsistent with type I, III or IV OI.
• History of known mutation in a gene other than collagen type I alpha 1/collagen type I alpha 2 (COL1A1/COL1A2) causing OI or other metabolic bone disease.
• History of congenital dislocation of the radial head, interosseous membrane calcification, or exuberant callus formation.

De-identified individual patient data for variables necessary to address the specific research question in an approved data sharing request.

Data sharing requests relating to this study will be considered beginning 18 months after the study has ended and either 1) the product and indication have been granted marketing authorization in both the US and Europe or 2) clinical development for the product and/or indication discontinues and the data will not be submitted to regulatory authorities. There is no end date for eligibility to submit a data sharing request for this study.

Qualified researchers may submit a request containing the research objectives, the Amgen product(s) and Amgen study/studies in scope, endpoints/outcomes of interest, statistical analysis plan, data requirements, publication plan, and qualifications of the researcher(s). In general, Amgen does not grant external requests for individual patient data for the purpose of re-evaluating safety and efficacy issues already addressed in the product labelling. Requests are reviewed by a committee of internal advisors. If not approved, a Data Sharing Independent Review Panel will arbitrate and make the final decision. Upon approval, information necessary to address the research question will be provided under the terms of a data sharing agreement. This may include anonymized individual patient data and/or available supporting documents, containing fragments of analysis code where provided in analysis specifications. Further details are available at the URL below.