Amunix Congratulates Versartis on its Positive Phase 2a Results with VRS-317

– Amunix XTEN Half-life Extension Technology Combined with Recombinant Human Growth Hormone Shows Positive Results in 6 Month Repeat-Dosing Clinical Trial –

Mountain View, CA – June 30, 2014 – Amunix Operating Inc., a biotechnology company developing a half-life extension technology for peptides, proteins and small molecules, congratulates Versartis, Inc. (NASDAQ:VSAR) on its positive clinical data with VRS-317, a novel, long-acting form of recombinant human growth hormone (rhGH).  Positive Phase 2a data from the Versartis six month clinical trial demonstrating the safety and efficacy of VRS-317 in the treatment of children with growth hormone deficiency (GHD) were recently presented at the ICE/ENDO conference. VRS-317, which is a new chemical entity, combines the same human growth hormone amino acid sequence utilized in currently approved human growth hormone products with Amunix’s protein–based XTEN half-life extension technology.  VRS-317 was designed to reduce the burden of daily injection therapy by requiring significantly fewer injections, potentially improving compliance and therefore treatment outcomes.   The proprietary XTEN technology was developed by Amunix and human growth hormones linked to XTEN, including VRS-317, are exclusively licensed worldwide to Versartis.

Volker Schellenberger, PhD, Amunix President and Chief Executive Officer, said,  “It is extremely gratifying to see our XTEN technology succeeding in human clinical trials, with the VRS-317 pediatric GHD study as the most recent example of the utility of our technology.  Current therapies for children with GHD require the burden of daily injections. The Versartis Phase 2a data demonstrate that the efficacy and safety of VRS-317, when administered monthly, semi-monthly and weekly in pediatric patients with GHD, are comparable to daily injections of human growth hormone at the highest approved dose on the labels of the current market leading therapies.”

Amunix has developed XTEN, a protein-based polymer that mimics the biophysical properties of PEG. XTEN is easily metabolized, thereby eliminating the risk of tissue accumulation. Single or multiple payloads can be conjugated or genetically fused to XTEN which allows the generation of monospecific, bispecific, as well as multivalent biopharmaceuticals.

About Amunix

Amunix Operating Inc., a biotechnology company headquartered in Mountain View, CA, has developed a novel half-life extension technology based on XTEN; hydrophilic, unstructured polypeptides which can be recombinantly fused or chemically conjugated to other peptides, proteins and small molecules.  Through this proprietary XTEN technology, the company creates and develops novel versions of clinically-proven pharmaceutical products that may offer better efficacy, safety and dosing frequency by extension of the half-life.  One XTEN product, Exenatide-XTEN (VRS-859), has completed a Phase I study through Amunix partner Diartis.  Amunix partner Versartis recently completed a Phase 2a clinical trial evaluating weekly, semi-monthly and monthly dosing regimens of hGH-XTEN (VRS-317) in children with growth hormone deficiency.  In addition, through its partnership with Biogen Idec, Amunix is developing Factor VIII and is working with Janssen Biotech, Inc. and its affiliates to apply the XTEN half-life extension technology with protein and/or peptide therapeutics selected by Janssen.  Amunix has several other undisclosed partners in various therapeutic areas.   Founded in 2006, Amunix is a profitable, independent biotechnology company with no external investors.  Amunix is actively seeking partnerships for application of its XTEN technology for half-life extension or tumor drug delivery. For additional information about the company, please visit www.amunix.com.