Broad spectrum influenza virus vaccine
The disclosure relates to broad spectrum influenza virus ribonucleic acid (RNA) vaccines, as well as methods of using the vaccines and compositions comprising the vaccine. In a preferred embodiment, the vaccine is formulated as a lipid nanoparticle comprising at least one cationic lipid.
1. A vaccine comprising:
(a) a first messenger ribonucleic acid (mRNA) polynucleotide comprising an open reading frame encoding a human influenza hemagglutinin (HA) protein;
(b) a second mRNA polynucleotide comprising an open reading frame encoding a human influenza protein selected from a nucleoprotein (NP), a neuraminidase (NA) protein, a matrix protein 1 (M1), a matrix protein 2 (M2), a nonstructural 1 (NS1) protein, and nonstructural 2 (NS2) protein; and
(c) a lipid nanoparticle comprising a compound of Formula (I):
or a salt or isomer thereof, wherein:
R 1 is selected from the group consisting of C 5-30 alkyl, C 5-20 alkenyl, —R*YR″, —YR″, and —R″M′R′;
R 2 and R 3 are independently selected from the group consisting of H, C 1-14 alkyl, C 2-14 alkenyl, —R*YR″, —YR″, and —R*OR″, or R 2 and R 3 , together with the atom to which they are attached, form a heterocycle or carbocycle;
R 4 is selected from the group consisting of a C 3-6 carbocycle, —(CH 2 ) n Q, —(CH 2 ) n CHQR, —CHQR, —CQ(R) 2 , and unsubstituted C 1-6 alkyl, where Q is selected from a carbocycle, heterocycle, —OR, —O(CH 2 ) n N(R) 2 , —C(O)OR, —OC(O)R, —CX 3 , —CX 2 H, —CXH 2 , —CN, —N(R) 2 , —C(O)N(R) 2 , —N(R)C(O)R, —N(R)S(O) 2 R, —N(R)C(O)N(R) 2 , —N(R)C(S)N(R) 2 , —N(R)R 8 , —O(CH 2 ) n OR, —N(R)C(═NR 9 )N(R) 2 , —N(R)C(═CHR 9 )N(R) 2 , —OC(O)N(R) 2 , —N(R)C(O)OR, —N(OR)C(O)R, —N(OR)S(O) 2 R, —N(OR)C(O)OR, —N(OR)C(O)N(R) 2 , —N(OR)C(S)N(R) 2 , —N(OR)C(═NR 9 )N(R) 2 , —N(OR)C(═CHR 9 )N(R) 2 , —C(═NR 9 )N(R) 2 , —C(═NR 9 )R, —C(O)N(R)OR, and —C(R)N(R) 2 C(O)OR, and each n is independently selected from 1, 2, 3, 4, and 5;
each R 5 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R 6 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
M and M′ are independently selected from —C(O)O—, —OC(O)—, —C(O)N(R′)—, —N(R′)C(O)—, —C(O)—, —C(S)—, —C(S)S—, —SC(S)—, —CH(OH)—, —P(O)(OR′)O—, —S(O) 2 —, —S—S—, an aryl group, and a heteroaryl group;
R 7 is selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
R 8 is selected from the group consisting of C 3-6 carbocycle and heterocycle;
R 9 is selected from the group consisting of H, CN, NO 2 , C 1-6 alkyl, —OR, —S(O) 2 R, —S(O) 2 N(R) 2 , C 2-6 alkenyl, C 3-6 carbocycle and heterocycle;
each R is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R′ is independently selected from the group consisting of C 1-18 alkyl, C 2-18 alkenyl, —R*YR″, —YR″, and H;
each R″ is independently selected from the group consisting of C 3-14 alkyl and C 3-14 alkenyl;
each R* is independently selected from the group consisting of C 1-12 alkyl and C 2-12 alkenyl;
each Y is independently a C 3-6 carbocycle;
each X is independently selected from the group consisting of F, Cl, Br, and I; and
m is selected from 5, 6, 7, 8, 9, 10, 11, 12, and 13.
2. The vaccine of claim 1 , wherein a subset of compounds of Formula (I) includes those in which when R 4 is —(CH 2 ) n Q, —(CH 2 ) n CHQR, —CHQR, or —CQ(R) 2 , then (i) Q is not —N(R) 2 when n is 1, 2, 3, 4 or 5, or (ii) Q is not 5, 6, or 7-membered heterocycloalkyl when n is 1 or 2.
3. The vaccine of claim 1 , wherein a subset of compounds of Formula (I) includes those in which
R 1 is selected from the group consisting of C 5-30 alkyl, C 5-20 alkenyl, —R*YR″, —YR″, and —R″M′R′;
R 2 and R 3 are independently selected from the group consisting of H, C 1-14 alkyl, C 2-14 alkenyl, —R*YR″, —YR″, and —R*OR″, or R 2 and R 3 , together with the atom to which they are attached, form a heterocycle or carbocycle;
R 4 is selected from the group consisting of a C 3-6 carbocycle, —(CH 2 ) n Q, —(CH 2 ) n CHQR, —CHQR, —CQ(R) 2 , and unsubstituted C 1-6 alkyl, where Q is selected from a C 3-6 carbocycle, a 5- to 14-membered heteroaryl having one or more heteroatoms selected from N, O, and S, —OR, —O(CH 2 ) n N(R) 2 , —C(O)OR, —OC(O)R, —CX 3 , —CX 2 H, —CXH 2 , —CN, —C(O)N(R) 2 , —N(R)C(O)R, —N(R)S(O) 2 R, —N(R)C(O)N(R) 2 , —N(R)C(S)N(R) 2 , —CRN(R) 2 C(O)OR, —N(R)R 8 , —O(CH 2 ) n OR, —N(R)C(═NR 9 )N(R) 2 , —N(R)C(═CHR 9 )N(R) 2 , —OC(O)N(R) 2 , —N(R)C(O)OR, —N(OR)C(O)R, —N(OR)S(O) 2 R, —N(OR)C(O)OR, —N(OR)C(O)N(R) 2 , —N(OR)C(S)N(R) 2 , —N(OR)C(═NR 9 )N(R) 2 , —N(OR)C(═CHR 9 )N(R) 2 , —C(═NR 9 )N(R) 2 , —C(═NR 9 )R, —C(O)N(R)OR, and a 5- to 14-membered heterocycloalkyl having one or more heteroatoms selected from N, O, and S which is substituted with one or more substituents selected from oxo (═O), OH, amino, mono- or di-alkylamino, and C 1-3 alkyl, and each n is independently selected from 1, 2, 3, 4, and 5;
each R 5 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R 6 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
M and M′ are independently selected from —C(O)O—, —OC(O)—, —C(O)N(R′)—, —N(R′)C(O)—, —C(O)—, —C(S)—, —C(S)S—, —SC(S)—, —CH(OH)—, —P(O)(OR′)O—, —S(O) 2 —, —S—S—, an aryl group, and a heteroaryl group;
R 7 is selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
R 8 is selected from the group consisting of C 3-6 carbocycle and heterocycle;
R 9 is selected from the group consisting of H, CN, NO 2 , C 1-6 alkyl, —OR, —S(O) 2 R, —S(O) 2 N(R) 2 , C 2-6 alkenyl, C 3-6 carbocycle and heterocycle;
each R is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R′ is independently selected from the group consisting of C 1-18 alkyl, C 2-18 alkenyl, —R*YR″, —YR″, and H;
each R″ is independently selected from the group consisting of C 3-14 alkyl and C 3-14 alkenyl;
each R* is independently selected from the group consisting of C 1-12 alkyl and C 2-12 alkenyl;
each Y is independently a C 3-6 carbocycle;
each X is independently selected from the group consisting of F, Cl, Br, and I; and
m is selected from 5, 6, 7, 8, 9, 10, 11, 12, and 13,
or salts or isomers thereof.
4. The vaccine of claim 1 , wherein a subset of compounds of Formula (I) includes those in which
R 1 is selected from the group consisting of C 5-30 alkyl, C 5-20 alkenyl, —R*YR″, —YR″, and —R″M′R′;
R 2 and R 3 are independently selected from the group consisting of H, C 1-14 alkyl, C 2-14 alkenyl, —R*YR″, —YR″, and —R*OR″, or R 2 and R 3 , together with the atom to which they are attached, form a heterocycle or carbocycle;
R 4 is selected from the group consisting of a C 3-6 carbocycle, —(CH 2 ) n Q, —(CH 2 ) n CHQR, —CHQR, —CQ(R) 2 , and unsubstituted C 1-6 alkyl, where Q is selected from a C 3-6 carbocycle, a 5- to 14-membered heterocycle having one or more heteroatoms selected from N, O, and S, —OR, —O(CH 2 ) n N(R) 2 , —C(O)OR, —OC(O)R, —CX 3 , —CX 2 H, —CXH 2 , —CN, —C(O)N(R) 2 , —N(R)C(O)R, —N(R)S(O) 2 R, —N(R)C(O)N(R) 2 , —N(R)C(S)N(R) 2 , —CRN(R) 2 C(O)OR, —N(R)R 8 , —O(C H 2 ) n OR, —N(R)C(═NR 9 )N(R) 2 , —N(R)C(═CHR 9 )N(R) 2 , —OC(O)N(R) 2 , —N(R)C(O)OR, —N(OR)C(O)R, —N(OR)S(O) 2 R, —N(OR)C(O)OR, —N(OR)C(O)N(R) 2 , —N(OR)C(S)N(R) 2 , —N(OR)C(═NR 9 )N(R) 2 , —N(OR)C(═CHR 9 )N(R) 2 , —C(═NR 9 )R, —C(O)N(R)OR, and —C(═NR 9 )N(R) 2 , and each n is independently selected from 1, 2, 3, 4, and 5; and when Q is a 5- to 14-membered heterocycle and (i) R 4 is —(CH 2 ) n Q in which n is 1 or 2, or (ii) R 4 is —(CH 2 ) n CHQR in which n is 1, or (iii) R 4 is —CHQR, and —CQ(R) 2 , then Q is either a 5- to 14-membered heteroaryl or 8- to 14-membered heterocycloalkyl;
each R 5 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R 6 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
M and M′ are independently selected from —C(O)O—, —OC(O)—, —C(O)N(R′)—, —N(R′)C(O)—, —C(O)—, —C(S)—, —C(S)S—, —SC(S)—, —CH(OH)—, —P(O)(OR′)O—, —S(O) 2 —, —S—S—, an aryl group, and a heteroaryl group;
R 7 is selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
R 8 is selected from the group consisting of C 3-6 carbocycle and heterocycle;
R 9 is selected from the group consisting of H, CN, NO 2 , C 1-6 alkyl, —OR, —S(O) 2 R, —S(O) 2 N(R) 2 , C 2-6 alkenyl, C 3-6 carbocycle and heterocycle;
each R is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R′ is independently selected from the group consisting of C 1-18 alkyl, C 2-18 alkenyl, —R*YR″, —YR″, and H;
each R″ is independently selected from the group consisting of C 3-14 alkyl and C 3-14 alkenyl;
each R* is independently selected from the group consisting of C 1-12 alkyl and C 2-12 alkenyl;
each Y is independently a C 3-6 carbocycle;
each X is independently selected from the group consisting of F, Cl, Br, and I; and
m is selected from 5, 6, 7, 8, 9, 10, 11, 12, and 13,
or salts or isomers thereof.
5. The vaccine of claim 1 , wherein a subset of compounds of Formula (I) includes those in which
R 1 is selected from the group consisting of C 5-30 alkyl, C 5-20 alkenyl, —R*YR″, —YR″, and —R″M′R′;
R 2 and R 3 are independently selected from the group consisting of H, C 1-14 alkyl, C 2-14 alkenyl, —R*YR″, —YR″, and —R*OR″, or R 2 and R 3 , together with the atom to which they are attached, form a heterocycle or carbocycle;
R 4 is selected from the group consisting of a C 3-6 carbocycle, —(CH 2 ) n Q, —(CH 2 ) n CHQR, —CHQR, —CQ(R) 2 , and unsubstituted C 1-6 alkyl, where Q is selected from a C 3-6 carbocycle, a 5- to 14-membered heteroaryl having one or more heteroatoms selected from N, O, and S, —OR, —O(CH 2 ) n N(R) 2 , —C(O)OR, —OC(O)R, —CX 3 , —CX 2 H, —CXH 2 , —CN, —C(O)N(R) 2 , —N(R)C(O)R, —N(R)S(O) 2 R, —N(R)C(O)N(R) 2 , —N(R)C(S)N(R) 2 , —CRN(R) 2 C(O)OR, —N(R)R 8 —O(CH 2 ) n OR, —N(R)C(═NR 9 )N(R) 2 , —N(R)C(═CHR 9 )N(R) 2 , —OC(O)N(R) 2 , —N(R)C(O)OR, —N(OR)C(O)R, —N(OR)S(O) 2 R, —N(OR)C(O)OR, —N(OR)C(O)N(R) 2 , —N(OR)C(S)N(R) 2 , —N(OR)C(═NR 9 )N(R) 2 , —N(OR)C(═CHR 9 )N(R) 2 , —C(═NR 9 )R, —C(O)N(R)OR, and —C(═NR 9 )N(R) 2 , and each n is independently selected from 1, 2, 3, 4, and 5;
each R 5 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R 6 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
M and M′ are independently selected from —C(O)O—, —OC(O)—, —C(O)N(R′)—, —N(R′)C(O)—, —C(O)—, —C(S)—, —C(S)S—, —SC(S)—, —CH(OH)—, —P(O)(OR′)O—, —S(O) 2 —, —S—S—, an aryl group, and a heteroaryl group;
R 7 is selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
R 8 is selected from the group consisting of C 3-6 carbocycle and heterocycle;
R 9 is selected from the group consisting of H, CN, NO 2 , C 1-6 alkyl, —OR, —S(O) 2 R, —S(O) 2 N(R) 2 , C 2-6 alkenyl, C 3-6 carbocycle and heterocycle;
each R is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R′ is independently selected from the group consisting of C 1-18 alkyl, C 2-18 alkenyl, —R*YR″, —YR″, and H;
each R″ is independently selected from the group consisting of C 3-14 alkyl and C 3-14 alkenyl;
each R* is independently selected from the group consisting of C 1-12 alkyl and C 2-12 alkenyl;
each Y is independently a C 3-6 carbocycle;
each X is independently selected from the group consisting of F, Cl, Br, and I; and
m is selected from 5, 6, 7, 8, 9, 10, 11, 12, and 13,
or salts or isomers thereof.
6. The vaccine of claim 1 , wherein subset of compounds of Formula (I) includes those in which
R 1 is selected from the group consisting of C 5-30 alkyl, C 5-20 alkenyl, —R*YR″, —YR″, and —R″M′R′;
R 2 and R 3 are independently selected from the group consisting of H, C 2-14 alkyl, C 2-14 alkenyl, —R*YR″, —YR″, and —R*OR″, or R 2 and R 3 , together with the atom to which they are attached, form a heterocycle or carbocycle;
R 4 is —(CH 2 ) n Q or —(CH 2 ) n CHQR, where Q is —N(R) 2 , and n is selected from 3, 4, and 5;
each R 5 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R 6 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
M and M′ are independently selected from —C(O)O—, —OC(O)—, —C(O)N(R′)—, —N(R′)C(O)—, —C(O)—, —C(S)—, —C(S)S—, —SC(S)—, —CH(OH)—, —P(O)(OR′)O—, —S(O) 2 —, —S—S—, an aryl group, and a heteroaryl group;
R 7 is selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R′ is independently selected from the group consisting of C 1-18 alkyl, C 2-18 alkenyl, —R*YR″, —YR″, and H;
each R″ is independently selected from the group consisting of C 3-14 alkyl and C 3-14 alkenyl;
each R* is independently selected from the group consisting of C 1-12 alkyl and C 1-12 alkenyl;
each Y is independently a C 3-6 carbocycle;
each X is independently selected from the group consisting of F, Cl, Br, and I; and
m is selected from 5, 6, 7, 8, 9, 10, 11, 12, and 13,
or salts or isomers thereof.
7. The vaccine of claim 1 , wherein a subset of compounds of Formula (I) includes those in which
R 1 is selected from the group consisting of C 5-30 alkyl, C 5-20 alkenyl, —R*YR″, —YR″, and —R″M′R′;
R 2 and R 3 are independently selected from the group consisting of C 1-14 alkyl, C 2-14 alkenyl, —R*YR″, —YR″, and —R*OR″, or R 2 and R 3 , together with the atom to which they are attached, form a heterocycle or carbocycle;
R 4 is selected from the group consisting of —(CH 2 ) n Q, —(CH 2 ) n CHQR, —CHQR, and —CQ(R) 2 , where Q is —N(R) 2 , and n is selected from 1, 2, 3, 4, and 5;
each R 5 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R 6 is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
M and M′ are independently selected from —C(O)O—, —OC(O)—, —C(O)N(R′)—, —N(R′)C(O)—, —C(O)—, —C(S)—, —C(S)S—, —SC(S)—, —CH(OH)—, —P(O)(OR′)O—, —S(O) 2 —, —S—S—, an aryl group, and a heteroaryl group;
R 7 is selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R is independently selected from the group consisting of C 1-3 alkyl, C 2-3 alkenyl, and H;
each R′ is independently selected from the group consisting of C 1-18 alkyl, C 2-18 alkenyl, —R*YR″, —YR″, and H;
each R″ is independently selected from the group consisting of C 3-14 alkyl and C 3-14 alkenyl;
each R* is independently selected from the group consisting of C 1-12 alkyl and C 1-12 alkenyl;
each Y is independently a C 3-6 carbocycle;
each X is independently selected from the group consisting of F, Cl, Br, and I; and
m is selected from 5, 6, 7, 8, 9, 10, 11, 12, and 13,
or salts or isomers thereof.
8. The vaccine of claim 1 , wherein a subset of compounds of Formula (I) includes those of Formula (IA):
or a salt or isomer thereof, wherein l is selected from 1, 2, 3, 4, and 5; m is selected from 5, 6, 7, 8, and 9; M 1 is a bond or M′; R 4 is unsubstituted C 1-3 alkyl, or —(CH 2 ) n Q, in which Q is OH, —NHC(S)N(R) 2 , —NHC(O)N(R) 2 , —N(R)C(O)R, —N(R)S(O) 2 R, —N(R)R 8 , —NHC(═NR 9 )N(R) 2 , —NHC(═CHR 9 )N(R) 2 , —OC(O)N(R) 2 , —N(R)C(O)OR, heteroaryl or heterocycloalkyl; M and M′ are independently selected from —C(O)O—, —OC(O)—, —C(O)N(R′)—, —P(O)(OR′)O—, —S—S—, an aryl group, and a heteroaryl group; and R 2 and R 3 are independently selected from the group consisting of H, C 1-14 alkyl, and C 2-14 alkenyl.
9. The vaccine of claim 1 , wherein the human influenza HA protein is an H1 subtype or an H3 subtype.
10. The vaccine of claim 1 , wherein the human influenza protein comprises neuraminidase (NA).
11. The vaccine of claim 1 , wherein the lipid nanoparticle further comprises a PEG-modified lipid, a sterol, and a non-cationic lipid.
12. The vaccine of claim 11 , wherein the lipid nanoparticle comprises 20-60 mol % cationic lipid, 0.5-15 mol % PEG-modified lipid, 25-55 mol % sterol, and 5-25 mol % non-cationic lipid.
13. The vaccine of claim 12 , wherein the non-cationic lipid is a neutral lipid and the sterol is a cholesterol.
14. The vaccine of claim 1 , wherein the first mRNA polynucleotide of (a) and/or the second mRNA polynucleotide of (b) comprise a chemical modification.
15. A method of inducing an immune response in a subject, the method comprising administering to the subject the vaccine of claim 1 in an amount effective to produce an antigen-specific immune response in the subject.
16. A method of inducing cross-reactivity against a variety of influenza strains in a mammal, the method comprising administering to the mammal in need thereof the vaccine of claim 1 .
17. The vaccine of claim 1 , wherein the cationic lipid of Formula (I) is Compound 25:
18. The vaccine of claim 14 , wherein the chemical modification is 1-methylpseudouridine.
19. The vaccine of claim 1 , wherein:
R 1 is R″M′R′ or C 5-20 alkenyl;
R 2 and R 3 are each independently selected from C 1-14 alkyl and C 2-14 alkenyl;
R 4 is —(CH 2 ) n Q, wherein Q is OH and n is selected from 3, 4, and 5;
M and M′ are each independently —OC(O)— or —C(O)O—;
R 5 , R 6 , and R 7 are each H;
R′ is a linear C 1-12 alkyl, or C 1-12 alkyl substituted with C 6-9 alkyl;
R″ is C 3-14 alkyl;
m is selected from 5, 6, 7, 8, 9, 10, 11, 12, and 13.
20. The vaccine of claim 19 , wherein:
R 1 is R″M′R′;
R 2 and R 3 are each independently C 1-14 alkyl;
R 4 is —(CH 2 ) n Q, wherein Q is OH and n is 4;
M and M′ are each independently —OC(O)—;
R 5 , R 6 , and R 7 are each H;
R′ is C 1-12 alkyl substituted with C 6-9 alkyl;
R″ is C 3-14 alkyl; and
m is 6.
21. The vaccine of claim 19 , wherein:
R 1 is C 5-20 alkenyl;
R 2 and R 3 are each independently C 1-14 alkyl;
R 4 is —(CH 2 ) n Q, wherein Q is OH and n is 3;
M is —C(O)O—;
R 5 , R 6 , and R 7 are each H; and
m is 6.
22. The vaccine of claim 12 , wherein:
R 1 is R″M′R′ or C 5-20 alkenyl;
R 2 and R 3 are each independently selected from C 1-14 alkyl and C 2-14 alkenyl;
R 4 is —(CH 2 ) n Q, wherein Q is OH and n is selected from 3, 4, and 5;
M and M′ are each independently —OC(O)— or —C(O)O—;
R 5 , R 6 , and R 7 are each H;
R′ is a linear C 1-12 alkyl, or C 1-12 alkyl substituted with C 6-9 alkyl;
R″ is C 3-14 alkyl;
m is selected from 5, 6, 7, 8, 9, 10, 11, 12, and 13.
23. The vaccine of claim 22 , wherein:
R 1 is R″M′R′;
R 2 and R 3 are each independently C 1-14 alkyl;
R 4 is —(CH 2 ) n Q, wherein Q is OH and n is 4;
M and M′ are each independently —OC(O)—;
R 5 , R 6 , and R 7 are each H;
R′ is C 1-12 alkyl substituted with C 6-9 alkyl;
R″ is C 3-14 alkyl; and
m is 6.
24. The vaccine of claim 22 , wherein:
R 1 is C 5-20 alkenyl;
R 2 and R 3 are each independently C 1-14 alkyl;
R 4 is —(CH 2 ) n Q, wherein Q is OH and n is 3;
M is —C(O)O—;
R 5 , R 6 , and R 7 are each H; and
m is 6.