Press Release

Amunix and PolyPeptide Enter Into Partnership to Produce XTEN® Peptide Conjugates for Evaluation by Third Parties for Pharmaceutical Therapeutics

MOUNTAIN VIEW, CA–(Marketwired – Oct 28, 2014) – Amunix Operating Inc., and PolyPeptide Laboratories, Inc. (PPL) have entered into a partnership under which Amunix’s proprietary recombinantly derived polypeptides (XTEN®) will be chemically conjugated to other peptides. Under the terms of the Agreement, PPL will produce XTENylated peptides for third-party entities to facilitate evaluation of the resulting conjugates as therapeutic compounds. XTEN is Amunix’s proprietary protein-based polymer that mimics the biophysical properties of PEG and is used to extend the half-life of genetically fused therapeutic proteins and peptides.

“This partnership with PPL significantly expands our ability to provide both custom and off-the-shelf XTENylated peptides to the biopharmaceutical and pharmaceutical industries,” said Volker Schellenberger, PhD, Amunix President and CEO. “We have been working with PPL to synthesize a number of XTENylated peptides, including an antiviral for our own research purposes and are very pleased to extend the relationship to provide this valuable service to others.”

Under the agreement, Amunix will supply PPL with bulk research-grade XTEN that can be utilized by PPL to XTENylate payload peptides for preclinical screening, evaluation, and feasibility studies as potential development candidates. PPL will offer small-scale, non-GMP custom synthesis, and XTENylation of peptides selected by the customer for evaluation under separate agreements entered into with PPL without having to disclose the identity of the peptide to Amunix. Upon completion of successful screening efforts, customers can access available capacities at Amunix and PPL for the required scaled-up cGMP quantities of XTEN and XTENylated peptide.

XTEN is a proprietary recombinant polypeptide that extends the in vivo half-life of therapeutics payloads. XTEN consists of naturally occurring hydrophilic amino acids and is biodegradable. Pharmaceuticals such as proteins, peptides and synthetic compounds can be XTENylated via chemical conjugation or genetic fusion. The XTEN platform technology is unique in that it offers better safety options than other half-life extension technologies for developing new therapeutics and minimizes immunogenicity risks due to its solubility and high hydrophilic properties.

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 an XTENylated 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

About PolyPeptide

The PolyPeptide Group, with sites in Denmark, France, India, Sweden and the USA, is one of the world’s leading independent contract manufacturers of therapeutic peptides. The Group offers its customers an almost unprecedented long-term security of supply with six GMP facilities worldwide and an exclusive focus on pharmaceutical peptide manufacture. For additional information about the company, please visit