Amunix and PolyPeptide Publish Multivalent Antiviral XTEN®-Peptide Conjugates in vivo Studies in American Chemical Society’s Journal “Bioconjugate Chemistry”
Mountain View, CA – July 23, 2014 – Amunix Operating Inc., a biotechnology company developing hydrophilic, unstructured polypeptides which can be recombinantly fused or chemically conjugated to other peptides, proteins and small molecules, said its research paper, “Multivalent Antiviral XTEN−Peptide Conjugates with Long in Vivo Half-Life and Enhanced Solubility” is now available online (http://pubs.acs.org/doi/abs/10.1021/bc500215m) and will be published in an upcoming issue of “Bioconjugate Chemistry.” The paper presents positive in vivo data demonstrating the feasibility and versatility of multivalent drug display through XTENylation using the approved anti-HIV drug T-20 (enfuvirtide or Fuzeon) as a model therapeutic payload.
XTEN, a protein-based polymer that mimics the biophysical properties of PEG, has been used to extend the half-life of genetically fused therapeutic proteins and peptides. To expand the applications of XTEN technology to half-life extension of other classes of molecules, XTEN protein polymers and methods for chemical XTENylation were developed. Monovalent, multivalent and bispecific XTEN conjugates with various payloads have been synthesized and tested for their biological activities. 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.
In its recently published paper, Amunix described the use of its proprietary XTEN technology to develop a versatile platform for the multivalent delivery of an antiviral peptide. As a genetically defined protein polymer, XTEN facilitates the incorporation of multiple copies of a drug at precisely specified positions along its length. The company used the approved anti-HIV drug T-20 as a model therapeutic peptide and conjugated it to XTEN in a number of formats to test the effects of drug valency and spacing on the antiviral activity of the conjugates. PolyPeptide Group, a custom peptide synthesis group, synthesized the peptide for Amunix, provided valuable input on the experiment design and co-authored the manuscript.
Volker Schellenberger, PhD, Amunix President and Chief Executive Officer, said, “Conjugation of T-20 to XTEN was found to greatly extend the in vivo half-life of the peptide in rats, and it was possible to tune the in vitro potency of the conjugates by varying the copy number and spacing of the peptides on XTEN. T-20 was also found to exhibit greatly enhanced solubility upon conjugation to XTEN. Based on these results, we believe that XTEN constitutes a promising platform for the discovery and characterization of a new class of ‘biobetter’ therapeutics and offers significant advantages for the development of these drugs.”
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.
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 www.polypeptide.com.
PLEASE NOTE: Research reported in this press release was supported by the National Institute of Allergy and Infectious Diseases of the National Institutes of Health under Award Number R43AI102765. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.