Lipid formulations for delivery of messenger RNA

1. A method of treating cystic fibrosis comprising

administering to subject in need of treatment a composition comprising an mRNA encoding a cystic fibrosis transmembrane conductance regulator (CFTR) protein encapsulated within a liposome such that the administering of the composition results in the expression of the CFTR protein encoded by the mRNA in one or more tissues affected by cystic fibrosis;

wherein the liposome comprises a cationic lipid of formula I-c:

or a pharmaceutically acceptable salt thereof,

wherein:

p is an integer of between 1 and 9, inclusive;

each instance of R 2 is independently hydrogen or optionally substituted C 1-6 alkyl;

each instance of R 6 and R 7 is independently a group of the formula (i), (ii), or (iii);

Formulae (i), (ii), and (iii) are:

wherein:

each instance of R′ is independently hydrogen or optionally substituted alkyl;

X is O, S, or NR X , wherein R X is hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, or a nitrogen protecting group;

Y is O, S, or NR Y , wherein R Y is hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, or a nitrogen protecting group;

R P is hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, optionally substituted heteroaryl, an oxygen protecting group when attached to an oxygen atom, a sulfur protecting group when attached to a sulfur atom, or a nitrogen protecting group when attached to a nitrogen atom; and

R L is optionally substituted C 1-50 alkyl, optionally substituted C 2-50 alkenyl, optionally substituted C 2-50 alkynyl, optionally substituted heteroC 1-50 alkyl, optionally substituted heteroC 2-50 alkenyl, optionally substituted heteroC 2-50 alkynyl, or a polymer.

2. The method of claim 1 , wherein the cationic lipid is cKK-E12:

3. The method of claim 1 , wherein the liposome further comprises one or more non-cationic lipids, one or more cholesterol-based lipids and/or one or more PEG-modified lipids.

4. The method of claim 3 , wherein the one or more non-cationic lipids are selected from DSPC (1,2-distearoyl-sn-glycero-3-phosphocholine), DPPC (1,2-dipalmitoyl-sn-glycero-3-phosphocholine), DOPE (1,2-dioleyl-sn-glycero-3-phosphoethanolamine), DOPC (1,2-dioleyl-sn-glycero-3-phosphotidylcholine) DPPE (1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine), DMPE (1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine), DOPG (,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol)).

5. The method of claim 3 , wherein the one or more cholesterol-based lipids are cholesterol and/or PEGylated cholesterol.

6. The method of claim 3 , wherein the liposome comprises cKK-E12, DOPE, cholesterol and DMG-PEG2K.

7. The method claim 1 , wherein the liposome has a size less than about 250 nm, 200 nm, 150 nm, 100 nm, 75 nm, or 50 nm.

8. The method of claim 1 , wherein the mRNA comprises one or more modified nucleotides, and wherein the one or more modified nucleotides comprise pseudouridine, N-1-methyl-pseudouridine, 2-aminoadenosine, 2-thiothymidine, inosine, pyrrolopyrimidine, 3-methyl adenosine, 5-methylcytidine, C-5 propynyl-cytidine, C-5 propynyl-uridine, 2-aminoadenosine, C5-bromouridine, C5-fluorouridine, C5-iodouridine, C5-propynyl-uridine, C5-propynyl-cytidine, C5-methylcytidine, 2-aminoadenosine, 7-deazaadenosine, 7-deazaguanosine, 8-oxoadenosine, 8-oxoguanosine, O(6)-methylguanine, and/or 2-thiocytidine.

9. The method of claim 1 , wherein the mRNA is unmodified.