A Clinical Trial to Evaluate the Safety and Efficacy of BMN 111 in Infants and Young Children With Achondroplasia

Open to people ages up to 59 months

• Diagnosis of ACH, confirmed by genetic testing
• Age 0 to < 60 months at study entry (Day 1)
• At least 6-month period of pretreatment growth assessment in Study 111-901 immediately before study entry (cohort 1 & 2) or at least 3 months of observation prior to treatment (cohort 3)

1. Have hypochondroplasia or short-stature condition other than achondroplasia (e.g., trisomy 21, pseudoachondroplasia, etc.)
2. Have any of the following:
3. Hypothyroidism or hyperthyroidism
4. Insulin-requiring diabetes mellitus
5. Autoimmune inflammatory disease (including celiac disease, systemic lupus erythematosus, juvenile dermatomyositis, scleroderma, etc.)
6. Inflammatory bowel disease
7. Autonomic neuropathy
8. Have a clinically significant finding or arrhythmia that indicates abnormal cardiac function or conduction or QTc-F > 450 msec on screening ECG
9. Have evidence of cervicomedullary compression (CMC) likely to require surgical intervention within 60 days of Screening as determined by the Investigator and informed by the following assessments:
10. Physical exam (eg, neurologic findings of clonus, opisthotonus, exaggerated reflexes, dilated facial veins)
11. Polysomnography (eg, severe central sleep apnea)
12. MRI indicating presence of severe CMC or spinal cord damage
13. Subject weight < 5.0 kg (cohort 1 & 2) or < 4.0 kg (cohort 3)
14. Treatment with growth hormone within 6-months prior to screening or prolonged treatment (> 3 months) at any time
15. Any history of spine or long-bone surgery or any bone-related surgery with chronic complications
16. Any history of limb-lengthening surgery or planned limb-lengthening during the study
17. Fracture of the long bones within 6 months prior to screening