CD52 OPTIMIZED Fc VARIANTS AND METHODS FOR THEIR GENERATION

1 . A protein comprising an Fc variant of a parent Fc polypeptide and an IgG polypeptide that has specificity for CD52, said Fc variant comprising at least one amino acid modification in the Sc region of said IgG polypeptide said modification occurring at a position selected from the group consisting of: 228, 230, 231, 232, 240, 244, 245, 247, 262, 263, 266, 271, 273, 275, 281, 284, 291, 299, 302, 304, 313, 323, 325, 328, 332, wherein said Fc variant protein exhibits altered effector function, wherein numbering is according to the EU index.

2 . A protein according to claim 1 , wherein said Fc variant comprises at least one substitution selected from the group consisting of: 234, 235, 239, 240, 243, 264, 266, 272, 274, 278, 325, 328, 330, and 332.

3 . A protein according to claim 1 , wherein said altered effector function is an increase in affinity of said Fc variant to FcγR.

4 . A protein according to claim 3 , wherein said Fc variant binds with greater affinity to a mouse FcγR.

5 . A protein according to claim 3 , wherein said FcγR is a human Fc receptor selected from the group consisting of FcγRI, FcγRIIa, FcγRIIb, FcγRIIc, and FcγRIIIa.

6 . A protein according to claim 3 , wherein said Fc variant binds with greater affinity to human FcγRI and FcγRIIIa, but exhibits unaltered affinity to a human receptor selected from the group consisting of FcγRIIa, FcγRIIb, and FcγRIIc.

7 . A protein according to claim 6 , wherein said Fc variant exhibits unaltered affinity to FcγRIIa, FcγRIIb, and FcγRIIc.

8 . A protein according to claim 3 , wherein the affinity increase for binding to one or more human FcγRII's is greater than the affinity increase for binding to human FcγRI or FγRIIIa.

9 . A protein according to claim 3 , wherein the affinity increase is the same for binding to FcγRIIa, FcγRIIb, and FcγRIIc.

10 . A protein according to claim 3 , wherein the affinity increase for binding to FcγRIIc is greater than the affinity increase for binding to FcγRIIb.

11 . A protein according to claim 3 , wherein said Fc variant binds with greater affinity to human FcγRIIa, but exhibits unaltered affinity to a human receptor selected from the group consisting of FcγRI, FcγRIIb, FcγRIIc, and F c γRIIIa.

12 . A protein according to claim 11 , wherein said Fc variant exhibits unaltered affinity to FcγRI, FcγRIIb, FcγRIIc, and FcγRIIIa.

13 . A protein according to any of claims 1 - 12 , wherein said Fc variant binds with greater affinity to FcRn.

14 . A protein according to any of claims 1 - 12 , wherein said Fc variant binds with unaltered affinity to FcRn.

15 . A protein according to any of claims 1 - 12 , wherein said Fc variant binds with reduced affinity to FcRn.

16 . A protein according to any of claims 1 - 12 , wherein said Fc variant binds with greater affinity to C1q or enhances CDC.

17 . A protein according to any of claims 1 - 12 , wherein said Fc variant binds with unaltered affinity to C1q or enhances CDC.

18 . A protein according to claim 1 , wherein said Fc variant further comprises an engineered glycoform.

19 . A protein according to claim 18 wherein said engineered glycoform comprises an altered level of fucosylation or bisecting oligosaccharides as compared to the parent Fc polypeptide.

20 . A protein according to claim 18 wherein said engineered glycoform improves effector function.

21 . A protein according to claim 1 , wherein said Fc variant modulates effector function as compared to the parent Fc polypeptide.

22 . A protein according to claim 21 , wherein said effector function is ADCC.

23 . A protein according to claim 22 , wherein said Fc variant improves ADCC in the presence of human effector cells as compared to said parent Fc polypeptide.

24 . A protein according to claim 22 wherein said ADCC improvement is an enhancement in potency such that the EC50 of said Fc variant is approximately 5-fold greater than that of said parent Fc polypeptide.

25 . A protein according to claim 23 , wherein said ADCC improvement is an enhancement in potency such that the EC50 of said Fc variant is between approximately 5-fold and 1000-fold greater than that of said parent Fc polypeptide.

26 . A protein according to claim 23 , wherein said ADCC improvement is an enhancement in efficacy such that the maximal ADCC is approximately 2-fold greater than that of said parent Fc polypeptide.

27 . A protein according to claim 26 , wherein said Fc variant improves ADCC in the presence of mouse effector cells as compared to said parent Fc polypeptide.

28 . A protein according to claim 21 , wherein said effector function is ADCP.

29 . A protein according to claim 28 , wherein said Fc variant improves ADCP as compared to said parent Fc polypeptide.

30 . A protein according to claim 25 or 29 , wherein CDC is unaffected.

31 . A protein according to claim 25 or 29 , wherein CDC is ablated.

32 . A protein according to claim 1 or 21 comprising a modification selected from the group consisting of 228E, 228K, 228Y, 228G, 230E, 230Y, 230G, 231E, 231K, 231Y, 231P, 231G, 232E, 232K, 232Y, 232G, 262E, 262F, 271D, 271E, 271N, 271Q, 271K, 271R, 271S, 271T, 271H, 271A, 271V, 271L, 271I, 271F, 271M, 271Y, 271W, 271G, 275L, 281D, 281K, 281Y, 281P, 284E, 284N, 284T, 284L, 284Y, 291D, 291E, 291Q, 291T, 291H, 291I, 291G, 299D, 299E, 299N, 299Q, 299K, 299R, 299L, 299F, 299M, 299Y, 299W, 299P, 299G, 304D, 304N, 304T, 304H, 304L, 325K, 325R, 325S, 325F, 325M, 325Y, 325W, 325P, 325G, 328D, 328D, 328K, 328R, 328S, 328T, 328V, 328I, 328Y, 328W, 328P, 328G, 332K, 332R, 332S, 332V, 332L, 332F, 332M, 332W, 332P, 332G, 336E, 336K, 336Y, 230A, 240A, 240I, 240M, 240T, 244H, 245A, 247G, 247V, 262A, 262E, 262I, 262T, 263A, 263I, 263M, 263T, 266A, 266I, 266M, 266T, 273I, 275W, 299A, 299E, 299F, 299H, 299I, 299L, 299S, 299V, 302I, 313F, 323I, 325A, 325D, 325E, 325H, 325I, 325L, 3250, 325T, 325V, 328A, 3280, 328E, 328F, 328H, 328I, 328M, 328N, 328Q, 328T, 328V, 332A, 332Q, 332E, 332H, 332N, 332Q, 332T, and 332Y.

33 . A protein according to claim 1 wherein said parent Fc polypeptide is an antibody comprising said Fc variant.

34 . A protein according to claim 1 wherein said Fc variant is an Fc fusion protein comprising said Fc variant.

35 . A pharmaceutical composition comprising a protein according to claim 1 and a pharmaceutically acceptable carrier.

36 . A method of treating a mammal in need of said treatment, comprising administering a variant protein of claim 1 .

37 . A protein according to claims 1 or 33 comprising at least one modification selected from the group consisting of A330L/I332E, D265F/N297E/I332, D265Y/N297D/I332E, D265Y/N297D/T299L/I332E, F241E/F243Q/V262T/V264F, F241E/F243Q/V262T/V264E/I332E, F241E/F243R/V262E/V264R, F241E/F243R/V262E/V264R/I332E, F241E/F243Y/V262T/V264R, F241E/F243Y/V262T/V264R/I332E, F241L/F243L/V262I/V264I, F241L/V262I, F241R/F243Q/V262T/V264R, F241R/F243Q/V262T/V264R/I332E, F241W/F243W/V262A/V264A, F241Y/F243Y/V262T/V264T, F241Y/F243Y/V262T/V264T/N297D/I332E, F243L/V262I/V264W, P243L/V264I, L328D/I332E, L328E/I332E, L328H/I332E, L328I/I332E, L328M/I332E, L328N/I332E, L328Q/I332E, L328T/I332E, L328V/I332E, N297D/A330Y/I332E, N297D/I332E, N297D/I332E/S239D/A330L, N297D/S298A/A330Y/I332E, N297D/T299E/I332E, N297D/T299F/I332E, N297D/T299H/I332E, N297D/T299I/I332E, N297D/T299L/I332E, N297D/T299V/I332E, N297E/I332E, N297S/I332E, P230A/E233D/I332, P244H/P245A/P247V, S239D/A330L/I332E, S239D/A330Y/I332E, S239D/A330Y/I332E/K326E, S239D/A330Y/I332E/K326T, S239D/A330Y/I332E/L234I, S239D/A330Y/I332E/L235D, S239D/A330Y/I332E/V240I, S239D/A330Y/I332E/V264T, S239D/A330Y/I332E/V266I, S239D/D265F/N297D/I332E, S239D/D265H/N297D/I332E, S239D/D265I/N297D/I332E, S239D/D265L/N297D/I332E, S239D/D265T/N297D/I332E, S239D/D0265V/N297D/I332E, S239D/D265Y/N297D/I332E, S239D/I332D, S2390/I332E, S239D/I332E/A330I, S239D/I332N, S239D/I332Q, S239D/N297D01332E, S239D/N297D/I332E/A330Y, S239D/N297D/I332E/A330Y/F241S/F243H/V262T/V264T, S239D/N297D/I332E/K326E, S239D/N297D/I332E/L235D, S239D/S298A/I332E, S239D/V264I/A330L/I332E, S239D/V264I/I332E, S239D/V264I/S298A/I332E, S239E/D265N, S239E/D265Q, S239E/I332D, S239E/I332E, S239E/I332N, S239E/I332Q, S239E/N297D/I332E, S239E/V264I/A330Y/I332E, S239E/V264I/I 332E, S239E/V264I/S298A/A330Y/I332E, S239N/A330L/I332E, S239N/A330Y/I332E, S239N/I332D, S239N/I332E, S239N/I332N, S239N/I332Q, S239N/S298A/I332E, S239Q/I332D, S239Q/I332E, S239Q/I332N, S239Q/I332Q, S239Q/V264I/I332E, S298A/I332E, V264E/N297D/I332E, V264I/A330L/I332E, V264I/A330Y/I332E, V264I/I332E, V264I/S298A/I332E, Y296D/N297D/I332E, Y296E/N297D/I332E, Y296H/N297D/I332E, Y296N/N297D/I332E, Y296Q/N297D/I332E, and Y296T/N297D/I332E.

38 . A protein according to claims 1 , 33 or 37 further comprising a modification selected from the group consisting of 227E, 227K, 227Y, 227G, 233N, 233Q, 233K, 233R, 233S, 233T, 233H, 233A, 233V, 233L, 233I, 233F, 233M, 233Y, 233W, 233G, 234K, 234R, 234S, 234A, 234M, 234W, 234P, 234G, 235E, 235K, 235R, 235A, 235M, 235W, 235P, 235G, 236D, 236E, 236N, 236Q, 236K, 236R, 236S, 236T, 236H, 236A, 236V, 236L, 236I, 236F, 236M, 236Y, 236W, 236P, 237D, 237E, 237N, 237Q, 237K, 237R, 237S, 237T, 237H, 237V, 237L, 237I, 237F, 237M, 237Y, 237W, 237P, 238D, 238E, 238N, 238Q, 238K, 238R, 238S, 238T, 238H, 233V, 238L, 238I, 238F, 238M, 238Y, 238W, 238G, 239Q, 239K, 239R, 239V, 239L, 239I, 239M, 239W, 239P, 239G, 241D, 241E, 241Y, 243E, 246D, 246E, 246H, 246Y, 249Q, 249H, 249Y, 255E, 255Y 258S, 258H, 258Y, 260D, 260E, 260H, 260Y, 264D, 264E, 264N, 264Q, 264K, 264R, 264S, 264H, 264W, 264P, 264G, 265Q, 265K, 265R, 265S, 265T, 265H, 265V, 265L, 265I, 265F, 265M, 265Y, 265W, 265P, 267E, 267Q, 267K, 267R, 267V, 267L, 267I, 267F, 267M, 267Y, 267W, 267P, 268D, 268E, 268Q, 268K, 268R, 268T, 268V, 268L, 268I, 268F, 268M, 268W, 26FP, 268G, 269K, 269S, 269V, 269I, 269M, 269W, 269P, 269G, 270R, 270S, 270L, 270I, 270F, 270M, 270Y, 270W, 270P, 270G, 272D, 272R, 272T, 272H, 272V, 272L, 272F, 272M, 272W, 272P, 272G, 274D, 274N, 274S, 274H, 274V, 274I, 274F, 274M, 274W, 274P, 274G, 276D, 276T, 276H, 276V, 276I, 276F, 276M, 276W, 276P, 276G, 278D, 278N, 278Q, 278R, 278S, 278H, 278V, 278L, 278I, 278M, 278P, 278G, 280K, 280L, 280W, 280P, 280G, 282E, 282K, 282Y, 282P, 282G, 283K, 283H, 283L, 283Y, 283P, 283G, 285D, 285E, 285Q, 285K, 285Y, 285W, 286E, 286Y, 286P, 286G, 288D, 288E 288Y, 290D, 290N, 290H, 290L, 290W, 292D, 292E, 292T, 292Y, 293N, 293R, 293S, 293T, 293H, 293V, 293L, 293I, 293F, 293M, 293Y, 293W, 293P, 293G, 294K, 294R, 294S, 294T, 294K, 294V, 294L, 294I, 294F, 294M, 294Y, 294W, 294P, 294G, 295D, 295E, 295N, 295R, 295S, 295T, 295H, 295V, 295I, 295F, 295M, 295Y, 295W, 295P, 295G, 296K, 296R, 296A, 296V, 296M, 296G, 297Q, 297K, 297R, 297T, 297H, 297V, 297L, 297I, 297F, 297M, 297Y, 297W, 297P, 297G, 298D, 298E, 298Q, 298K, 298R, 298I, 298F, 298M, 298Y, 298W, 300D, 300E, 300N, 300Q, 300K, 300R, 300S, 300T, 300H, 300A, 300V, 300M, 300W, 300P, 300G, 301D, 301E, 301H, 301Y, 303D, 303E, 303Y, 305E, 305T, 305Y, 317E, 317Q, 318Q, 318H, 318L, 318Y, 320N, 320S, 320H, 320V, 320L, 320F, 320Y, 320W, 320P, 320G, 322D, 322S, 322V, 322I, 322F, 322Y, 322W, 322P, 322G, 324H, 324F, 324M, 324W, 324P, 324G, 326P, 327E, 327K, 327R, 327H, 327V, 327I, 327F, 327M, 327Y, 327W, 327P, 329D, 329E, 329N, 329Q, 329K, 329R, 329S, 329T, 329H, 329V, 329L, 329I, 329M, 329Y, 329W, 329G, 330E, 330N, 330T, 330P, 330G, 331D, 331Q, 331R, 331T, 331L, 331I, 331F, 331M, 331Y, 331W, 333L, 333F, 333M, 333P, 334P, 335N, 335S, 335H, 335V, 335L, 335I, 335F, 335M, 335W, 335P, 335G, 337E, 337N, 337H, 233D, 234D, 234E, 234F, 234H, 234I, 234N, 234Q, 234T, 234V, 234Y, 235D, 235F, 235H, 235I, 235N, 235Q, 235S, 235T, 235V, 235Y, 239D, 239E, 239F, 239H, 239N, 239Q, 239T, 239Y, 241E, 241L, 241R, 241S, 241W, 241Y, 243H, 243L, 243Q, 243R, 243W, 243Y, 264A, 264E, 264F, 264I, 264L, 264M, 264R, 264T, 264W, 264Y, 266F, 265G, 265K, 265I, 265L, 265N, 265Q, 265T, 265V, 265Y, 267D, 267H, 267L, 267N, 267Q, 267T, 269F, 269H, 269L, 269N, 269R, 269T, 269Y, 270H, 270Q, 270T, 272I, 272K, 272S, 272Y, 274E, 274L, 274R, 274T, 274Y, 276E, 276L, 276R, 276S, 276Y, 278E, 278K, 273T, 278W, 283R, 296D, 296E, 296H, 296I, 296L, 296N, 296Q, 296S, 296T, 297D, 297E, 297S, 298A, 298H, 298N, 298T, 318R, 320D, 320I, 320T, 322H, 322T, 324D, 324I, 324L, 324R, 324T, 324V, 324Y, 326E, 326I, 326L, 326T, 327D, 327L, 327N, 327S, 327T, 329F, 330F, 330H, 330I, 330L, 330M, 330R, 330S, 330V, 330W, 330Y, 331H, 331V, 333A, 333H, 333I, 333T, 333Y, 334A, 334F, 334I, 334T, 335D, 335R, and 335Y.

39 . A protein according to claim 1 wherein said Fc variant further comprises a set of modifications selected from 241W/243W, 267Q/327S, 243L/264I, 234I/235D, 264E/297D/332E, 239E/265N, 239E/265Q, 239E/265G, 267L/327S and 240I/266I.

40 . A protein according to claim 33 wherein said antibody is a full length antibody.

41 . A protein according to claim 33 wherein said antibody is a human antibody.

42 . A protein according to claim 33 wherein said antibody is an antibody fragment.