Neutralizing anti-influenza B antibodies and uses thereof

1. An isolated antibody or an antigen binding fragment thereof comprising a variant Fc region, wherein the antibody or antigen binding fragment thereof is capable of binding to influenza B virus hemagglutinin (HA) and neutralizing influenza B virus in two phylogenetically distinct lineages and has an enhanced serum half-life relative to a native Fc antibody, wherein the antibody or antigen binding fragment thereof includes a set of six CDRs: HCDR-1, HCDR-2, HCDR-3, LCDR-1, LCDR-2, LCDR-3, in which the set of six CDRs comprises HCDR-1 of SEQ ID NO.: 145, HCDR-2 of SEQ ID NO.: 146, HCDR-3 of SEQ ID NO.: 147, LCDR-1 of SEQ ID NO.: 148, LCDR-2 of SEQ ID NO.: 149 and LCDR-3 of SEQ ID NO.: 150.

2. The isolated antibody or antigen binding fragment thereof according to claim 1 , wherein the antibody or antigen binding fragment thereof is capable of binding to Yamagata lineage influenza B virus selected from: B/AA/94 (ca B/Ann Arbor/2/94 (yamagata)); B/YSI/98 (ca B/Yamanashi/166/98 (yamagata)); B/JHB/99 (ca B/Johannesburg/5/99 (yamagata)); B/SC/99 (B/Sichuan/379/99 (yamagata)); B/FL/06 (B/Florida/4/2006 (yamagata)); Victoria lineage influenza B virus selected from: B/BJ/97 (ca B/Beijing/243/97 (victoria)), B/HK/01 (B/Hong Kong/330/2001 (victoria)); B/MY/04 (B/Malaysia/2506/2004 (victoria)); B/BNE/08 (ca B/Brisbane/60/2008 (victoria)); pre-divergent influenza B strains selected from: B/Lee/40 (B/Lee/40); B/AA/66 (ca B/Ann Arbor/1/66); B/HK/72 (B/Hong Kong/5/72); and combinations thereof.

3. The isolated antibody or antigen binding fragment thereof according to claim 1 , wherein the antibody is capable of binding to influenza A virus hemagglutinin.

4. The isolated antibody or antigen binding fragment thereof according to claim 3 , wherein the antibody is capable of binding to influenza A virus subtype 1 or subtype 2 hemagglutinin.

5. The isolated antibody or antigen binding fragment thereof according to claim 4 , wherein the antibody is capable of binding to influenza A virus group 1 subtype selected from: H8, H9, H11, H12, H13, H16 and variants thereof.

6. The antibody or antigen binding fragment thereof according claim 1 comprising a VH having at least 75%, 80%, 85%, 90%, 95% or 100% identity to a VH of SEQ ID NO: 62 and a VL having at least 75%, 80%, 85%, 90%, 95% or 100% identity to a VL of SEQ ID NO: 67.

7. The antibody or antigen binding fragment thereof according to claim 1 comprising a VH of SEQ ID NO: 62 and a VL of SEQ ID NO: 67.

8. An isolated nucleic acid encoding an antibody or antigen binding fragment thereof according to claim 1 .

9. A vector comprising an isolated nucleic acid according to claim 8 .

10. A host cell comprising a nucleic acid according to claim 9 .

11. A method for manufacturing an antibody or antigen binding fragment thereof that is capable of binding to influenza B virus hemagglutinin (HA) and neutralizing influenza B virus in two phylogenetically distinct lineages, the method comprising culturing a host cell comprising a nucleic acid according to claim 8 under conditions suitable for expression of the antibody or fragment thereof.

12. A composition comprising an antibody or antigen binding fragment thereof according to claim 1 and 25 mM His and 0.15M NaCl at pH 6.0.

13. A method for prophylaxis or treatment of influenza B infection in a subject comprising administering an effective amount of an antibody or antigen binding fragment thereof according to claim 1 to the subject.

14. A method for prophylaxis or treatment of influenza A and influenza B infection in a subject comprising administering an effective amount of an antibody or antigen binding fragment thereof according to claim 1 to the subject.

15. The use of an antibody or fragment thereof according to claim 1 for in vitro diagnosis of influenza B infection in a subject.

16. The isolated antibody or antigen binding fragment thereof according to claim 1 , wherein the variant Fc region comprises a modification at one or more positions selected from 221, 225, 228, 234, 235, 236, 237, 238, 239, 240, 241, 243, 244, 245, 247, 250, 251, 252, 254, 255, 256, 257, 262, 263, 264, 265, 266, 267, 268, 269, 279, 280, 284, 292, 296, 297, 298, 299, 305, 308, 313, 316, 318, 320, 322, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 339, 341, 343, 370, 373, 378, 392, 416, 419, 421, 428, 433, 434, 435, 436, 440, and 443 as numbered by the EU index as set forth in Kabat.

17. The isolated antibody or antigen binding fragment thereof according to claim 16 , wherein the modification is selected from a substitution, insertion and a deletion.

18. The isolated antibody or antigen binding fragment thereof according to claim 1 , wherein the variant Fc region includes at least one substitution selected from 221K, 221Y, 225E, 225K, 225W, 228P, 234D, 234E, 234N, 234Q, 234T, 234H, 234Y, 234I, 234V, 234F, 235A, 235D, 235R, 235W, 235P, 235S, 235N, 235Q, 235T, 235H, 235Y, 235I, 235V, 235E, 235F, 236E, 237L, 237M, 237P, 239D, 239E, 239N, 239Q, 239F, 239T, 239H, 239Y, 240I, 240A, 240T, 240M, 241W, 241L, 241Y, 241E, 241R, 243W, 243L 243Y, 243R, 243Q, 244H, 245A, 247L, 247V, 247G, 250E, 250Q, 251F, 252L, 252Y, 254S, 254T, 255L, 256E, 256F, 256M, 257C, 257M, 257N, 262I, 262A, 262T, 262E, 263I, 263A, 263T, 263M, 264L, 264I, 264W, 264T, 264R, 264F, 264M, 264Y, 264E, 265A, 265G, 265N, 265Q, 265Y, 265F, 265V, 265I, 265L, 265H, 265T, 266I, 266A, 266T, 266M, 267Q, 267L, 268E, 269H, 269Y, 269F, 269R, 270E, 280A, 284M, 292P, 292L, 296E, 296Q, 296D, 296N, 296S, 296T, 296L, 296I, 296H, 296G, 297S, 297D, 297E, 298A, 298H, 298I, 298T, 298F, 299I, 299L, 299A, 299S, 299V, 299H, 299F, 299E, 305I, 308F, 313F, 316D, 318A, 318S, 320A, 320S, 322A, 322S, 325Q, 325L, 325I, 325D, 325E, 325A, 325T, 325V, 325H, 326A, 326D, 326E, 326G, 326M, 326V, 327G, 327W, 327N, 327L, 328S, 328M, 328D, 328E, 328N, 328Q, 328F, 328I, 328V, 328T, 328H, 328A, 329F, 329H, 329Q, 330K, 330G, 330T, 330C, 330L, 330Y, 330V, 330I, 330F, 330R, 330H, 331G, 331A, 331L, 331M, 331F, 331W, 331K, 331Q, 331E, 331S, 331V, 331I, 331C, 331Y, 331H, 331R, 331N, 331D, 331T, 332D, 332S, 332W, 332F, 332E, 332N, 332Q, 332T, 332H, 332Y, 332A, 333A, 333D, 333G, 333Q, 333S, 333V, 334A, 334E, 334H, 334L, 334M, 334Q, 334V, 334Y, 339T, 370E, 370N, 378D, 392T, 396L, 416G, 419H, 421K, 428L, 428F, 433K, 433L, 434A, 434W, 434Y, 436H, 440Y and 443W as numbered by the EU index as set forth in Kabat.

19. The isolated antibody or antigen binding fragment thereof according to claim 1 , wherein the variant Fc region comprises:

(a) at least one modification at one or more positions selected from 228, 234, 235 and 331 as numbered by the EU index as set forth in Kabat;

(b) at least one modification at one or more positions selected from 228 and 235 as numbered by the EU index as set forth in Kabat;

(c) at least one modification at one or more positions selected from 239, 330 and 332 as numbered by the EU index as set forth in Kabat; or

(d) at least one modification at one or more positions selected from 252, 254, and 256 as numbered by the EU index as set forth in Kabat.

20. The isolated antibody or antigen binding fragment thereof according to claim 1 , wherein the variant Fc region comprises:

(a) one or more substitutions selected from 228P, 235E and 235Y as numbered by the EU index as set forth in Kabat;

(b) one or more substitutions selected from 239D, 330L, 330Y, and 332E as numbered by the EU index as set forth in Kabat;

(c) one or more substitutions selected from 252Y, 254T and 256E as numbered by the EU index as set forth in Kabat; or

(d) one or more substitutions selected from 228P, 234F, 235E, 235F, 235Y, and 331S as numbered by the EU index as set forth in Kabat.

21. The isolated antibody or antigen binding fragment thereof according to claim 1 , wherein the variant Fc region comprises an IgG4 Fc region.

22. The isolated antibody or antigen binding fragment thereof according to claim 1 , wherein the variant Fc region comprises three substitutions: 252Y, 254T and 256E as numbered by the EU index as set forth in Kabat.