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.
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
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.
6
Treatment groupsSee each treatment group below.