An observational study in Achondroplasia, sponsored by BioMarin Pharmaceutical. Recruiting at 8 sites in United States. Open to participants aged 0 Months to 18 Years. Per ClinicalTrials.gov, last updated 2026-06-30.
Sponsored by BioMarin Pharmaceutical · Observational
This is an observational study of individuals with achondroplasia in the United States. The primary study population consists of pediatric individuals treated and untreated with VOXZOGO™. Study enrollment started in February 2023. The projected total duration of the study is approximately 5 years at minimum from start of study recruitment in February 2023, with the duration of individual prospective follow-up differing depending on the time of enrollment. The study duration may be extended based on decisions by the study sponsor.
Data will be collected in two formats for the primary pediatric study population:
Data will be collected in the following format for the adult cohort:
- Participant-mediated access to electronic health records (including medical imaging, when available) which will enable retrospective and prospective collection of secondary data reflecting real-life treatment use and clinical care.
The primary study population will include approximately 150 pediatric individuals with achondroplasia regardless of their treatment status with VOXZOGO™. Individuals may change status from untreated to treated during the prospective period of the study (or vice versa) however they will only be counted once, based on their treated status at the point of enrollment.
The secondary study population will include 20 adolescent and adult participants.
47 studies on the registry are indexed under Achondroplasia; 13 are open to participants now.
This study's planned enrollment of 170 is below the median of 200 across 19 observational studies indexed under Achondroplasia.
Browse Achondroplasia studies →BioMarin Pharmaceutical is the lead sponsor of 112 studies on the registry; 13 are open to participants now.
Of its 17 completed or terminated interventional studies of FDA-regulated products, 12 (71%) have results posted.
Counted across the registry records on this site, refreshed daily.
The primary study population will include individuals with achondroplasia regardless of their treatment status with VOXZOGO™. Whilst individuals may change status from untreated to treated during the prospective period of the study (or vice versa), for the purposes of recruitment targets they will only be counted once, based on their treated status at the point of enrollment
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Primary Pediatric Cohort: ≤13 years old Secondary Adolescent and Adult Cohort: ≥14 years old
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
≤13 years old at time of enrollment. This is an observational study.
≥14 years old at time of enrollment. This is an observational study.
Height
sitting and standing measured in centimetres
Time frame: Retrospective data and prospective data for up to 5 years starting from time of study enrolment
Weight
measured in kilograms
Time frame: Retrospective data and prospective data for up to 5 years starting from time of study enrolment
Body Mass Index
measured in kg/m2
Time frame: Retrospective data and prospective data for up to 5 years starting from time of study enrolment
Head Circumference
measured in centimeters
Time frame: Retrospective data and prospective data for up to 5 years starting from time of study enrolment
Annualized growth velocity (AGV)
measured in centimeters/year
Time frame: Retrospective data and prospective data for up to 5 years starting from time of study enrolment
Medical diagnoses by age
Clinical examination and/or radiological assessment
Time frame: Retrospective data and prospective data for up to 5 years starting from time of study enrolment
Surgical procedures and/or medical interventions by age
Time frame: Retrospective data and prospective data for up to 5 years starting from time of study enrolment
Changes in physical functioning
assessed using the Mobility and Upper Extremity Patient-Reported Outcomes Measurement Information System (PROMIS) tools
Time frame: every 6 months starting from time of study enrolment up to 5 years
Changes in health-related quality of life (HRQoL)
assessed using the Pediatric Quality of Life Inventory (PedsQL)
Time frame: every 6 months starting from time of study enrolment up to 5 years
Adherence to treatment with VOXZOGO™ (vosoritide), if prescribed
assessed using a medication adherence questionnaire to capture the number of missed doses in the prior month. Parent(ObsRO) version for all participants enrolled ages 5-13 years
Time frame: every 6 months starting from time of study enrolment up to 5 years
Started Feb 2023 (actual). Primary completion is estimated for Feb 2028, 60 months after the start.
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