PolyXen is a patent-protected enabling platform technology designed for protein or peptide therapeutics. It uses the natural polymer polysialic acid (PSA) to prolong a drug's circulating half-life and potentially improve other pharmacological properties. PolyXen has been demonstrated in human clinical trials to confer extended half-life to biotherapeutics such as recombinant human erythropoietin (rhEPO) and recombinant Factor VIII (rFVIII).
Xenetic is leveraging PolyXen to partner with biotechnology and pharmaceutical companies. The Company receives royalty payments under an exclusive license arrangement in the field of blood coagulation disorders. In addition, Xenetic’s partner, PJSC Pharmsynthez ("Pharmsynthez"), is leveraging the Company’s PolyXen® technology to improve the pharmacological properties of its Epolong (erythropoietin and polysialic acid conjugate) product candidate pursuant to a royalty-bearing collaboration agreement between the Company's wholly owned subsidiary, Lipoxen Technologies Limited, and Pharmsynthez's wholly owned subsidiary, SynBio LLC. Pharmsynthez has reported that it has started the registration phase of Epolong by filing a registration dossier to obtain approval of Epolong in Russia for the treatment of anemia in patients with chronic kidney disease. The registration dossier is based on previously reported data from Pharmsynthez's Phase 3 clinical trials of Epolong in Russia, which reportedly demonstrated the efficacy of Epolong and its potential to reduce side effects.