Pharmaceutical composition
(19) AUSTRALIAN PATENT OFFICE (54) (51)G Title Pharmaceutical composition International Patent Classification(s) A61K 9/1G (2006.01) 39/00 AGIK 39/00 (2006.01)20060101ALI2006092 A61K 39/07 (2006.01)2BHEP A61K A61K 9/16 39/07 20060101AFI2006092 20060101ALI2006092 2BHEP A61K 2BHEP PCT/GB2006/000751 Application No: 2006219717 WIPONo: WO06/092607 (22) Application Date: 2006.03.02 (21)(87)(30) (31)(43) (71) (72) (74) Priority Data Number 0511801.3 0504276.7 Publication Date : (32) Date 2005.06.10 2005.03.02 2006.09.08 (33) Country GB GB Applicant(s) The Secretary of State for Defence Inventor(s) Elvin, Stephen J.; Healey, Gareth David; Westwood, Angela; Eyles, James Edward Agent/Attorney Davies Collison Cave, 1 Nicholson Street Melbourne, VIC, 3000 (57) Abstract: A microparticle composition comprising a biodegradable polymer, an immunogenic single stranded ribonucleic acid (ss-RNA) material, a biologically active macromolecule and a stabilising agent wherein the outer surface of the resulting microparticle is free from adsorbed molecules is described. The composition is effective in providing an immune response in dendritic ells, in particular by stimulating increased production of IFN ct. Methods of production and uses, in medicine, of pharmaceutical compositions derived from the microparticles are also claimed and described. A microparticle composition comprising (a) a biodegradable polymer; (b) an immunogenic single-stranded ribonucleic acid (ss-RNA); (c) a biologically active macromolecule; and (d) a stabilising agent; wherein the biologically active macromolecule, the single-stranded ribonucleic acid (ss-RNA) and the stabilising agent are encapsulated inside and/or within the biodegradable polymer to provide a free outer surface of the microparticle.
A microparticle composition according to claim 1 wherein the biodegradable polymer is biocompatible and degrades in mammalian tissues.
A microparticle composition according to either of claims 1 or 2 wherein the biodegradable polymer is an aliphatic polyester.
A microparticle composition according to claims 1 to 3 wherein the biodegradable polymer is poly-lactide.
A microparticle composition according to any preceding claim wherein the immunogenic ss-RNA is capable of stimulating production of proinflammatory and/or anti-viral cytokines.
A microparUcle composition according to claim 5 wherein the ss-RNA stimulates production of anti-viral cytokines A microparticle composition according to claim 6 wherein the antiviral cytokines are INF-a and/or INF-13 and/or IL-12.
A microparUcle composition according to any of claims 1 to 7 wherein the ssRNA is capable of stimulating the Toll-Like Receptors (TLR) of a host cell. 9. A microparticle composition according to claim 8 wherein the ss-RNA stimulates TLR-7 and/or TLR-8. 10. A microparticle composition according to any preceding claim wherein the ss-RNA has a sequence which is predominately rich in a single base 11. A microparticle composition according to claim 10 wherein the ss-RNA sequence is predominately made up of Guanine and/or Uracil. 12. A microparticle composition according to claims 10 or 11 wherein the ss-RNA is polyuridylic acid. 13. A microparticle composition according to any preceding claim wherein the biologically active macromolecule is an oligodeoxynucleotide or an antigen specific to a pathogen. 14. A microparticle composition according to claim 13 wherein the biologically active macromolecule is an antigen specific to a bacterial or viral pathogen. 15. A pharmaceutical composition according to claim 13 or 14 wherein the biologically active macromolecule is recombinant Protective Antigen (rPA) of Bacillus anthracis. 16. A microparticle composition according to any preceding claim wherein the biologically active macromolecule is an antigen expressed on a tumour cell. 17. A microparticle composition according to any of the preceding claims wherein the stabilising agent is pharmaceutically acceptable compound which is capable of forming a complex with the ss-RNA. 18. A microparticle composition according to claim 17 wherein the stabilising agent is a cationic polymer or a cationic lipid. 19. A microparticle composition according to claims 17 or 18 wherein the stabilising agent is N-[1-(2,3-dioleoyloxy)propyl]-N,N,Ntrimethylammonium chloride. 20. A microparticle composition according to any preceding claim wherein the composition has an overall net positive charge. 21. A microparticle composition according to claim 20 wherein the composition has a zeta potential in the range of 0 to 100 mV, preferably in the range of 20 to 80 mV and more preferably in the range of 30 to 60 inV. 22. A microparticle composition according to any preceding claim wherein the resulting microparticles have mean diameter in the range of 0.1 to 5 tm and more preferably in the range of 0.2 to 4 m. 23. A microparticle composition according to claim 22 wherein the microparticles have mean diameter of about 1 m. 24. A method of producing the microparticle composition of claims 1 to 23 comprising the steps of:
(a) preparing a solution of biodegradable polymer; (b) adding to the solution of (a), a solution comprising an immunogenic ssRNA and a biologically active macromolecule to form an aqueous-organic emulsion; (c) adding the emulsion from step (b) to a solution containing the stabilising agent to form a double emulsion; (d) removing organic solvent from the double emulsion of(c); and (e) collecting the resulting microparticles. 25. A method according to claim 24 wherein the microparticles are further subjected to the step of lyophilisation. 26. A pharmaceutical composition comprising the microparticle composition according to any of claims 1 to 23 and a pharmaceutically acceptable adjuvant and/or excipient. 27. A pharmaceutical composition according to claim 26, for use in medicine. 28. Use of a pharmaceutical composition according to claim 26 in the manufacture of a medicament for the treatment of pathogenic infection. 29. Use of a pharmaceutical composition according to claim 26 in the manufacture of a medicament for stimulation of Toll-Like Receptors of a host cell. 30. Use of a pharmaceutical composition according to claim 26 in the manufacture of a medicament for the treatment of cancer. 31. A microparticle composition according to claim 1, a method of producing a microparticle composition according to claim 24, a pharmaceutical composition according to claim 26 or a use of a pharmaceutical composition according to any one of claims 28 to 30, substantially as hereinbefore described with reference to the Examples and!or Figures.