Study to Evaluate the Efficacy and Safety of BMN 333 Versus Vosoritide in Children With Achondroplasia

NCT07441876 | Recruiting Phase 2 DMC FDA Drug

• 1 other identifier: 333-301
• Study Type: interventional
• Target: 160
• Locations: 1 country
• Sites: 2

Brief Summary

This is a multicenter, multinational, randomized, active-controlled, operationally seamless Phase 2/3 study of BMN 333 in treatment-naïve pediatric participants with achondroplasia (ACH). The study consists of a Phase 2 part and a Phase 3 part.

Conditions

Achondroplasia

Keywords

Achondroplasia; ACH; Bone Diseases, Developmental Dwarfism; Bone Diseases; Genetic Diseases, Inborn; Musculoskeletal Diseases; Natriuretic Peptide, C-type; Osteochondrodysplasias; Physiological Effects of Drugs; Skeletal Dysplasias

Outcome Measures

Primary Outcomes (2)

• Phase 2: Predicted Annualized Growth Velocity (AGV) at Week 52 (based on AGV at Weeks 26, 39, and 52 [available cumulative data]

  52 weeks

• Phase 3: Annualized Growth Velocity (AGV) at Week 52

  52 weeks

Secondary Outcomes (16)

• Phase 2: AGV at Weeks 26 and 52

  26 and 52 weeks

• Phase 2: Change from Baseline in standing height

  26 and 52 weeks

• Phase 2: Change from Baseline in height Z-score

  26 and 52 weeks

• Phase 2: Change from Baseline in upper to lower body segment ratio

  26 and 52 weeks

• Phase 2: Incidence of adverse events (AEs)

  52 weeks

Study Arms (6)

Phase 2: Low Dose

EXPERIMENTAL

Participants will be randomized to receive different dose levels of BMN 333

Drug: BMN 333

Phase 2: Medium Dose

EXPERIMENTAL

Participants will be randomized to receive different dose levels of BMN 333

Drug: BMN 333

Phase 2: High Dose

EXPERIMENTAL

Participants will be randomized to receive different dose levels of BMN 333

Drug: BMN 333

Phase 2: Vosoritide

ACTIVE COMPARATOR

weight band dosing, Modified recombinant human C-type natriuretic peptide Vosoritide

Drug: Vosoritide Injection [Voxzogo]

Phase 3: BMN 333 at selected dose after Phase 2

EXPERIMENTAL

Drug: BMN 333

Phase 3: Vosoritide

ACTIVE COMPARATOR

weight band dosing, Modified recombinant human C-type natriuretic peptide Vosoritide

Drug: Vosoritide Injection [Voxzogo]

Interventions

BMN 333 DRUG

Administration: Weekly subcutaneous injection

Phase 2: High Dose; Phase 2: Low Dose; Phase 2: Medium Dose; Phase 3: BMN 333 at selected dose after Phase 2

Vosoritide Injection [Voxzogo] DRUG

Administration: Daily subcutaneous injection

Phase 2: Vosoritide; Phase 3: Vosoritide

Eligibility Criteria

• Age: 2 Years - 17 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Participants must be aged ≥ 2 to \< 11 years (Phase 2) or ≥ 2 to \< 18 years (Phase 3), at the time of signing the informed consent
• Participants must have ACH (confirmed by documented genetic testing) and open epiphyses
• Are Tanner Stage I (Phase 2) or any Tanner stage (Phase 3)
• Are ambulatory and able to stand without assistance

You may not qualify if:

• Have any short stature condition other than ACH (eg, hypochondroplasia, trisomy 21, pseudoachondroplasia, GH deficiency)
• Have any of the following disorders: Hypothyroidism or hyperthyroidism, unless treated with evidence of normalized thyroid-stimulating hormone (TSH) levels, diabetes mellitus, unless considered well-controlled, autoimmune inflammatory disease, inflammatory bowel disease, autonomic neuropathy, anemia defined as hemoglobin \< 10 g/dL, vitamin D deficiency, significant hip pathology.
• Have history of any renal insufficiency or cardiac/ cardiovascular disease that places the participant at increased risk of an adverse cardiac outcome in the setting of hypotension.
• Have had bone fractures of the long bones or spine within 6 months prior to screening.
• Have used vosoritide, any other approved product (except GH, as detailed below), investigational product, or investigational medical device for the treatment of ACH or short stature at any time
• Have been treated with GH, insulin-like growth factor 1, or anabolic steroids in the 6 months prior to treatment start

Sponsors & Collaborators

• BioMarin Pharmaceutical: lead

Study Sites (2)

UCSF Benioff Children's Hospital Oakland

Oakland, California, 94609, United States

RECRUITING

Texas Children Hospital, Baylor College of Medicine, Houston TX

Houston, Texas, 77030, United States

RECRUITING

MeSH Terms

Conditions

Achondroplasia; Bone Diseases; Genetic Diseases, Inborn; Musculoskeletal Diseases; Osteochondrodysplasias

Interventions

vosoritide

Condition Hierarchy (Ancestors)

Dwarfism; Bone Diseases, Developmental; Congenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

• Medical Director, PhD

  BioMarin Pharmaceutical

  STUDY DIRECTOR

Central Study Contacts

Trial Specialist

CONTACT

1-800-983-4587; medinfo@bmrn.com

Study Manager

CONTACT

1-800-983-4587; Medinfo@bmrn.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: February 11, 2026
• First Posted: March 2, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): June 1, 2029
• Study Completion (Estimated): September 1, 2029
• Last Updated: April 22, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will share

Locations

US (2)