A Study of BMN 333 compared with Vosoritide in Children with Achondroplasia
Research type
Research Study
Full title
A Multicenter, Randomized, Operationally Seamless Phase 2/3 Study to Evaluate the Efficacy and Safety of BMN 333 versus Vosoritide in Children with Achondroplasia
IRAS ID
1013456
Contact name
Helen Watson
Contact email
Sponsor organisation
BioMarin Pharmaceutical Inc
Research summary
Rationale: The purpose of this study, which includes 2 parts, is to see how BMN 333 affects the growth of children with achondroplasia compared with vosoritide.
Objectives: The aim of Part 1 of the study is to see which of 3 doses of BMN 333 is best at improving the growth of children with achondroplasia. Part 2 of the study will then evaluate how the best dose of BMN 333 affects growth compared with vosoritide.
Main Study Endpoints: Part 1 will evaluate how fast children with achondroplasia grow when given 1 of the 3 different doses of BMN 333 for a minimum of 6 months compared with children treated with vosoritide. Part 2 will evaluate how fast children with achondroplasia grow when given the best dose of BMN 333 identified in Part 1 for 1 year compared with children treated with vosoritide.
Study Design: In Part 1, children will be randomly placed into 1 of 4 groups with an equal chance of being in any group, and will receive 1 of 3 doses of BMN 333 or vosoritide for 1 year. The children in the BMN 333 groups (and the study site staff) will know they are getting BMN 333 but will not know which dose, and children in the vosoritide group (and the study site staff) will know they are getting vosoritide. In Part 2, a new set of children will be randomly placed into 1 of 2 groups with an equal chance of being in either one, and will receive either the best dose of BMN 333 identified in Part 1 or vosoritide for 1 year. Children will know if they are receiving BMN 333 or vosoritide. Children who finish this study will be invited to join a separate study where they will receive the best dose of BMN 333 until they have finished growing.
Study Population: Part 1 of the study will include 40 children aged 2 to 10 years. Part 2 of the study will include 120 children aged 2 to 17 years.
Interventions: In both Part 1 and Part 2, children will be given either BMN 333 weekly or vosoritide daily for 1 year. Both treatments will be given as an injection under the skin.REC name
West Midlands - Edgbaston Research Ethics Committee
REC reference
26/WM/0032
Date of REC Opinion
7 Apr 2026
REC opinion
Further Information Favourable Opinion