The primary endpoint of non-inferiority to daily therapy in the pediatric Phase 3 study was not achieved

Protocol 13VR3 is is a multi-center, open-label study assessing long-term somavaratan administration.

Patients will be monitored for safety throughout their participation in the study. Safety will be monitored by physical examination, inspection of injection sites, vital signs, clinical laboratory determinations (including fasting glucose, insulin, and lipids), 12-lead ECGs (for new treatment naïve subjects and subjects not previously exposed to somavaratan), PK/PD assessments, and immunogenicity assessments.

Adverse events (AEs) and concomitant medications will be captured. AEs will be coded using CTCAE v 4.0. AEs will be coded using the MedDRA dictionary and CMs using the WHO Drug dictionary.

Protocol 13VR3 is a multi-center, open-label study assessing long-term somavaratan administration. It is open to subjects completing a somavaratan study in children with growth hormone deficiency (GHD), as well as up to 100 new treatment naïve subjects with GHD. All subjects will receive somavaratan 3.5 mg/kg twice monthly. The study will be conducted at approximately 70 Pediatric Endocrinology centers in the United States, Canada, and Europe.

Inclusion Criteria for Subjects Completing a Previous Somavaratan Study:

1. Completion of a somavaratan clinical study.
2. Willing and able to comply with all study procedures.

Exclusion Criteria for Subjects Completing a Previous somavaratan Study:

1. Withdrawal from a somavaratan clinical study.
2. Use of certain medications with potential to alter responses to the test product.
3. Presence of a significant medical condition.

Inclusion Criteria for New Treatment Naïve Subjects:

1. Chronological Age ≥ 3.0 years.
2. Pre-pubertal status.
3. Diagnosis of GHD as documented by two or more GH stimulation test results ≤ 10.0 ng/mL.
4. Normal thyroid function at Screening Visit in subjects not being treated for hypothyroidism.
5. Normal adrenal function at Screening Visit or within 6 months of the Screening Visit, in subjects not being treated for adrenal insufficiency. Subjects with adrenal insufficiency must receive glucocorticoid treatment for a minimum of 4 weeks before study drug administration.
6. Pathology relating to cause of GHD must be stable for at least 6 months prior to screening.
7. Legally authorized representatives must be willing and able to give informed consent.

Exclusion Criteria for New Treatment Naïve Subjects:

1. Prior/concomitant treatment with any growth promoting agent.
2. Current, significant disease.
3. Chromosomal aneuploidy, significant gene mutations or confirmed diagnosis of a named syndrome.
4. Birth weight and/or birth length less than 5th percentile for gestational age.
5. Prolonged daily use of anti-inflammatory doses of oral glucocorticoids.
6. Prior history of malignancy.
7. Treatment with an investigational drug in the 30 days prior to screening.
8. Known allergy to constituents of the study drug formulation.
9. Ocular findings suggestive of increased intracranial pressure and/or retinopathy at screening.
10. Significant spinal abnormalities including scoliosis, kyphosis, Chiari malformation, and spina bifida variants.
11. Significant abnormality in screening studies.
12. History of pancreatitis or undiagnosed chronic abdominal pain.
13. History of spinal or total body irradiation.
14. Other pituitary hormone deficiencies that are not properly treated.