Open-label Extension Study to Evaluate the Safety of Long-term Twice-monthly Administration of Somavaratan in AGHD

An open-label extension study to evaluate the safety of long-term twice-monthly
administration of somavaratan in adults with Growth Hormone Deficiency (GHD). This
multicenter study is open to subjects completing a Versartis adult GHD study as well as
approximately 40 new somavaratan naïve subjects (either rhGH treatment naïve or currently
receiving daily rhGH therapy). All subjects will receive twice-monthly (every 15 days ± 2
days) subcutaneous (SC) somavaratan. Doses will be titrated to each subject's individual
IGF-I responses based on the IGF-I level 7 days post-dose until a maintenance dose is
achieved. Subjects receiving somavaratan in a previous somavaratan study will have their dose
decreased by half (minimum dose of 20 mg, 40 mg for women on estrogen, rounded down to the
nearest even number) and will be titrated per the Dose Titration Plan. New subjects enrolling
in this study will be assigned to one of two cohorts based on sensitivity to rhGH and
titrated per the Dose Titration Plan.

Inclusion Criteria:

- Female subjects of childbearing potential must have negative pregnancy test and use
appropriate contraceptive methods

- Documented GHD during adulthood

- Subjects naive to somavaratan must have an IGF-1 SDS value ≤ 0 at Screening

- Subjects taking other hormone replacement therapy must have been on a stable course of
treatment for at least 3 months

- Underlying disorders responsible for the subject's GHD must have been clinically
stable for at least 6 months

- Subjects receiving daily rhGH injections must washout for ≥ 14 days

- BMI (kg/m2) between 18.0 and 40.0

Exclusion Criteria:

- Untreated adrenal insufficiency

- Recently diagnosed thyroid dysfunction which is not being treated or has not been
stable on therapy for at least 3 months

- Currently taking anti-inflammatory dose of glucocorticoids that could potentially
compromise safety or efficacy assessments

- Currently taking a GHRH or IGF-I product

- Current significant cardiovascular disease, heart insufficiency of New York Heart
Association (NYHA) class > 2

- Current significant disease thought to increase risk of receiving growth hormone or
confound assessment of study outcomes

- History of diabetes mellitus or inadequate glucose control

- Current drug or alcohol abuse

- Current HIV wasting syndrome (HIV testing not required)

- History of malignancy in adulthood (subjects with a history of childhood malignancy
that were subsequently treated with rhGH in childhood and remain GHD in adulthood may
be enrolled)

- Women who are pregnant or breastfeeding

- Treatment with an investigational drug other than somavaratan within 30 days prior to
Screening

- A significant abnormality in Screening laboratory results