An Extension Study to Evaluate the Efficacy and Safety of BMN 111 in Children With Achondroplasia

Inclusion Criteria:

• Must have completed Study 111-301

• Female >= 10 years old or who have begun menses must have a negative pregnancy testat the Baseline Visit and be willing to have additional pregnancy tests during thestudy

• If sexually active, willing to use a highly effective method of contraception whileparticipating in the study

• Are willing and able to perform all study procedures

• Parent(s) or guardian(s) are willing and able to provide written, signed informedconsent after the nature of the study has been explained and prior to performance ofany research-related procedure. Also, subjects under the age of majority are willingand able to provide written assent (if required by local regulations or the IRB/IEC)after the nature of the study has been explained and prior to performance of anyresearch-related procedure. Subjects who reach the age of majority in their countrywhile the study is ongoing will be asked to provide their own written consent againupon reaching the legal age of majority.

Exclusion Criteria:

• Permanently discontinued BMN 111 or placebo prior to completion of the 111-301 study

• Have a clinically significant finding or arrhythmia on Baseline ECG that indicatesabnormal cardiac function

• Evidence of decreased growth velocity (<1.5 cm/year) as assessed over a period of atleast 6 months or of growth plate closure (proximal tibia, distal femur) throughbilateral lower extremity X-rays.

• Require any investigational agent prior to completion of study period

• Current therapy with medications known to alter renal function

• Pregnant or breastfeeding or plan to become pregnant during study

• Concurrent disease or condition that, in the view of the investigator, wouldinterfere with study participation or safety evaluations, for any reason.

• Have a condition or circumstance that, in the view of the investigator, places thesubject at high risk for poor treatment compliance or for not completing the study.