Versartis Initiates VERTICAL Trial Of Long Acting Human Growth Hormone In Children With Growth Hormone Deficiency

Positive VRS-317 Phase I Study in Adults Supports First Pediatric Clinical Trial

Redwood City, CA--(Marketwire) - Versartis, Inc., an emerging biotechnology company developing novel therapeutics for patients with endocrine disorders, announced today that it has begun its first pediatric clinical trial of VRS-317, the company's proprietary once monthly form of recombinant human growth hormone (rhGH), in children with Growth Hormone Deficiency (GHD). The Versartis Trial In Children to Assess Long-Acting Growth Hormone (VERTICAL) study is being conducted in up to 26 sites in the United States and was initiated following the successful completion of a Phase I study in adults with GHD.

"I am very excited to participate in the VERTICAL Trial in children with GHD because my patients would greatly benefit from a long acting human growth hormone," said Paul Saenger, MD, Emeritus Professor of Pediatrics, Albert Einstein College of Medicine and Attending Physician at Winthrop-University Hospital. "As a clinician, I know that for children diagnosed with GHD, the burden of daily injections is a key impediment to optimal treatment outcomes. VRS-317 is currently the only long acting rhGH compound with the potential for once monthly dosing."

Phase 1b/2a Study in Pediatric Patients
The VERTICAL study is a randomized, open-label, multi-center Phase 1b/2a study being conducted in pre-pubertal GHD children that have not been previously treated with rhGH. The study is designed in two stages: the first stage (Phase Ib) utilizes an ascending dose design to evaluate the safety and tolerability of up to four dosing levels of a single subcutaneous (SC) dose of VRS-317 in approximately 48 pre-pubertal GHD children. The second stage (Phase 2a) will further study these patients to determine the efficacy of VRS-317 as defined by an increase in height velocity over six months of treatment. Secondary objectives of the six-month Phase 2a study include evaluating the safety and tolerability of repeat dosing as well as change in bone age, body weight and other measures of growth.

VRS-317 Phase 1 Clinical Trial Results
The clinical data from the Phase I study of VRS-317 were recently provided in an oral presentation at ESPE 2012: The 51st Annual Meeting of the European Society for Paediatric Endocrinology in Leipzig, Germany on September 25. The primary objective of the Phase 1 study was to evaluate the safety and tolerability of a single SC dose of VRS-317. The double-blind, randomized, placebo-controlled, single-ascending dose Phase 1 trial enrolled 50 adult GHD patients in the United States and Europe.

Results were presented by George M. Bright, MD, Vice President of Medical Affairs at Versartis, and demonstrated that single doses of VRS-317 were safe and well tolerated. Adverse events (AEs) that were considered drug related were primarily mild and transient, with no reported SAEs and no unexpected AEs. PK and PD results were presented for all dose levels in the study. The half-life of VRS-317 increased significantly (p=0.016) as a linear function of increased dose with a maximum mean terminal half-life of 131 hours at the 0.80 mg/kg dose of VRS-317. Adult GHD patients with a pre-dose IGF-1 SDS below -1.5 had a mean sustained IGF-1 SDS above -1.5 for up to three weeks after a single 0.80 mg/kg VRS-317 dose. The data also demonstrated that single doses of VRS-317 sustained IGF-1 responses in the normal range in a dose dependent and tunable manner, enabling dose regimens of up to monthly for future clinical trials.

About Versartis
Versartis, Inc. is a biotechnology company developing therapeutics for the treatment of endocrine disorders. The company's lead product candidate is VRS-317, a once monthly form of human growth hormone. Versartis is pursuing the development of new therapeutic proteins utilizing the proprietary Amunix half-life extension XTEN technology. XTEN is a novel hydrophilic sequence of natural amino acids and is expressed as a fusion protein with a therapeutically active peptide or protein. New compounds developed by Versartis using the XTEN technology are expected to provide improved therapeutic outcomes such as enhanced efficacy/compliance, fewer side effects, prolonged half-life (up to monthly dosing), as well as low-cost production and enhanced stability. Further information on Versartis can be found atwww.versartis.com.