Small liposomes for delivery of immunogen encoding RNA

Patent metadata

Field	Value
Publication number	US-9254265-B2
Application number	US-201113819245-A
Country	US
Kind code	B2
Filing date	Aug 31, 2011
Priority date	Aug 31, 2010
Publication date	Feb 9, 2016
Grant date	Feb 9, 2016

Abstract

Nucleic acid immunization is achieved by delivering RNA encapsulated within a liposome. The RNA encodes an immunogen of interest, and the liposome has a diameter in the range of 60-180 nm, and ideally in the range 80-160 nm. Thus the invention provides a liposome having a lipid bilayer encapsulating an aqueous core, wherein: (i) the lipid bilayer has a diameter in the range of 60-180 nm; and (ii) the aqueous core includes a RNA which encodes an immunogen. These liposomes are suitable for in vivo delivery of the RNA to a vertebrate cell and so they are useful as components in pharmaceutical compositions for immunizing subjects against various diseases.

First claim

The invention claimed is:

1. A pharmaceutical composition comprising a population of liposomes and a population of immunogen-encoding RNA molecules,
wherein the average diameter of the liposomes in the population is about 100 nm, with a polydispersity index of less than about 0.1, wherein said population of liposomes comprise: (i) 20%-80% (molar percent) cationic lipid or lipids; (ii) a zwitterionic lipid; and (iii) 20%-80% (molar percent) cholesterol; wherein at least half of the population of RNA molecules are encapsulated in liposomes, wherein said population of RNA molecules are self-replicating RNA molecules that encode (a) a RNA-dependent RNA polymerase which can transcribe RNA from the self-replicating RNA and (b) an immunogen, and wherein said population of RNA molecules are not packaged in virion particles.

2. The liposome of claim 1 , wherein the RNA is 5000-25000 nucleotides long.

3. The liposome of claim 1 , wherein the self-replicating RNA is a (+)-stranded RNA.

4. The liposome of claim 1 , wherein the self-replicating RNA has two open reading frames, the first of which encodes an alphavirus replicase and the second of which encodes the immunogen.

5. The liposome of claim 2 , wherein the self-replicating RNA is 9000-12000 nucleotides long.

6. The liposome of claim 1 , wherein the immunogen can elicit an immune response in vivo against a bacterium, a virus, a fungus or a parasite.

7. A pharmaceutical composition comprising a liposome of claim 1 .

8. The pharmaceutical composition of claim 7 , wherein said population of liposomes comprise 35%-50% (molar percent) cholesterol.

9. The liposome of claim 1 , wherein said liposome comprises DlinDMA (1,2-dilinoleyloxy-N,N-dimethyl-3-aminopropane), DSPC (1,2-Diastearoyl-sn-glycero-3-phosphocholine), DPyPE (1,2-diphytanoyl-sn-glycero-3-phosphoethanolamine), a cholesterol, a PEGylated lipid, or a combination thereof.

10. The pharmaceutical composition of claim 1 , wherein said population of liposomes comprise 35%-50% (molar percent) cholesterol.

11. The pharmaceutical composition of claim 1 , wherein said population of liposomes comprise 30%-70% (molar percent) cationic lipid or lipids.

12. A method for raising a protective immune response in a vertebrate, comprising the step of administering to the vertebrate an effective amount of the pharmaceutical composition of claim 1 .

Assignees

• Geall Andrew
• Verma Ayush
• Novartis Ag

Inventors

• Geall Andrew
• Verma Ayush

Classifications

• C12N2770/36143

  viral genome or elements thereof as genetic vector · CPC title

• A61K9/1277

  Preparation processes; Proliposomes · CPC title

• A61P31/12

  Antivirals · CPC title

• A61K9/1272

  comprising non-phosphatidyl surfactants as bilayer-forming substances, e.g. cationic lipids or non-phosphatidyl liposomes coated or grafted with polymers (lipids as modifying agents {A61K47/543}) · CPC title

• A61K2039/53

  DNA (RNA) vaccination · CPC title