Amunix, Versartis Presents Data For XTEN

Amunix and Versartis have reported that the scientific journal Nature Biotechnology has published a comprehensive paper entitled ‘A recombinant polypeptide extends the in vivo half-life of peptides and proteins in a tunable manner.’

The paper describes the design of Amunix’s polypeptide sequence XTEN and presents preclinical data for Versartis’ product candidates VRS-859 as a monthly-dosed treatment for type 2 diabetes and VRS-317 as a monthly-dosed treatment for growth hormone deficiency.

The published data demonstrate that XTEN, a technology for half-life extension, can provide an effective means for prolonging the in vivo half-life of therapeutic peptides and proteins. With a longer half-life, patients have improved convenience and compliance with comparable efficacy to the drug without XTEN.

XTEN is an unstructured recombinant polypeptide that is genetically fused to a peptide or protein. The XTEN sequence has been specifically designed to have low immunogenicity and good manufacturability, making it a generic platform technology applicable to a wide variety of peptide and protein therapeutics. The publication presents, for the first time, the example case of the exenatide peptide fused to XTEN, with a projected human half-life of 139 hours, and preclinical data on human growth hormone fused to XTEN with a half-life in monkeys of 110 hours.

Willem Stemmer, CEO of Amunix, said: “Based on data from several peptides and proteins fused to XTEN, we expect that XTEN will enable dosing of otherwise rapidly cleared protein drugs at up to monthly intervals in humans.”

Jeffrey Cleland, CEO of Versartis, said: “These peer-reviewed results further validate that the monthly-dosed exenatide (VRS-859) and human growth hormone (VRS-317) products provide significant advantages over other approaches on the market or in clinical trials.”