HUMANIZED ANTI-5T4 ANTIBODIES AND ANTI-5T4/CALICHEAMICIN CONJUGATES
Chimeric and humanized anti-5T4 antibodies and antibody/drug conjugates and methods for preparing and using the same.
1 . A chimeric or humanized anti-5T4 antibody comprising at least one light chain and at least one heavy chain, or a chimeric or humanized fragment thereof, wherein the antibody or antibody fragment
specifically binds to human 5T4 antigen with a binding affinity characterized by a KD of 1.2×10 −10 M or greater biding affinity.
2 . The chimeric or humanized anti-5T4 antibody or antibody fragment of claim 1 comprising constant regions derived from human constant regions.
3 . The chimeric or humanized anti-5T4 antibody or antibody fragment of claim 2 , wherein the human light chain constant region is derived from human kappa light chain constant region.
4 . The chimeric or humanized anti-5T4 antibody or antibody fragment of claim 2 , wherein the human heavy chain constant region is derived from a human IgG1 or human IgG4 heavy chain constant region.
5 . The chimeric or humanized anti-5T4 antibody or antibody fragment of claim 4 , wherein the human IgG1 heavy chain constant region comprises an amino acid sequence of any one of SEQ ID NOs:25 or 85-89.
6 . The chimeric or humanized anti-5T4 antibody or antibody fragment of claim 4 , wherein the human IgG4 heavy chain constant region comprises proline at position 241.
7 - 10 . (canceled)
11 . The humanized anti-5T4 antibody or antibody fragment of claim 1 , wherein the variable region of the at least one light chain or at least one heavy chain comprises:
(a) framework regions comprising residues of a human antibody framework region; and
(b) one or more CDRs of the light chain variable region of SEQ ID NO:17 or one or more CDRs of the heavy chain variable region of SEQ ID NO:18.
12 . The humanized anti-5T4 antibody or antibody fragment of claim 11 , wherein the framework regions comprise:
(a) a human antibody light chain framework region of a DPK24 subgroup IV germ line clone, a VκIII subgroup, or a VκI subgroup germ line clone;
(b) a human antibody heavy chain framework region selected from the group consisting of DP-75, DP-8 (VH1-2), DP-25, VI-2b and VI-3 (VH1-03), DP-15 and V1-8 (VH1-08), DP-14 and V1-18 (VH1-18), DP-5 and V1-24P (VH1-24), DP-4 (VH1-45), DP-7 (VH1-46), DP-10, DA-6 and YAC-7 (VH1-69), DP-88 (VH1-e), DP-3 and DA-8 (VH1-f);
(c) a consensus sequence of a heavy chain framework region of (b); or
(d) a framework region that is at least 95% identical to a framework region of (a)-(c).
13 . The humanized anti-5T4 antibody or antibody fragment of claim 11 comprising at least two CDRs of SEQ ID NOs:17 or 18.
14 . The humanized anti-5T4 antibody or antibody fragment of claim 13 , wherein the light chain comprises a variable region comprising at least two of three CDRs of SEQ ID NO:17.
15 . The humanized anti-5T4 antibody or antibody fragment of claim 14 , wherein the light chain comprises a variable region comprising three CDRs of SEQ ID NO:17.
16 . The humanized anti-5T4 antibody or antibody fragment of claim 11 , wherein the heavy chain comprises a variable region comprising at least two of three CDRs of SEQ ID NO:18.
17 . The humanized anti-5T4 antibody or antibody fragment of claim 16 , wherein the heavy chain comprises a variable region comprising three CDRs of SEQ ID NO:18.
18 . The humanized anti-5T4 antibody or antibody fragment of claim 11 , wherein the light chain comprises the CDRs of SEQ ID NOs:17-18.
19 . The humanized anti-5T4 antibody or antibody fragment of claim 1 , wherein the light chain variable region sequence comprises:
(a) an amino acid sequence of SEQ ID NO:23; or
(b) an amino acid sequence that is at least 81% identical to SEQ ID NO:23.
20 . The humanized anti-5T4 antibody or antibody fragment of claim 1 , wherein the light chain variable region sequence is encoded by a nucleic acid comprising:
(a) a nucleotide sequence of SEQ ID NO:22;
(b) a nucleotide sequence that is at least 90% identical to the nucleic acid of SEQ ID NO:22; or
(c) a nucleic acid that specifically hybridizes to the complement of SEQ ID NO:22 under stringent hybridization conditions.
21 . The humanized anti-5T4 antibody or antibody fragment of claim 1 , wherein the heavy chain variable region sequence comprises:
(a) an amino acid sequence set forth as SEQ ID NO: 19 or 21;
(b) an amino acid sequence that is at least 81% identical to SEQ ID NO:19; or
(c) an amino acid sequence that is at least 86% identical to SEQ ID NO:21.
22 . The humanized anti-5T4 antibody or antibody fragment of claim 1 , wherein the heavy chain variable region sequence is encoded by a nucleic acid comprising:
(a) a nucleotide sequence of SEQ ID NO:20 or 83;
(b) a nucleotide sequence that is at least 91% identical to the nucleic acid of SEQ ID NO:20 or SEQ ID NO:83; or
(c) a nucleic acid that specifically hybridizes to the complement of SEQ ID NO: 20 or 83 under stringent hybridization conditions.
23 - 49 . (canceled)
50 . A chimeric or humanized anti-5T4 antibody comprising at least one light chain and at least one heavy chain, or a chimeric or humanized fragment thereof, comprising a light chain variable region sequence comprising:
(a) an amino acid sequence of SEQ ID NO: 23;
(b) an amino acid sequence that is at least 81% identical to SEQ ID NO:23;
(c) a nucleotide sequence of SEQ ID NO:22;
(d) a nucleotide sequence that is at least 90% identical to the nucleic acid of SEQ ID NO:22; or
(e) a nucleic acid that specifically hybridizes to the complement of SEQ ID NO:22 under stringent hybridization conditions.
51 . A chimeric or humanized anti-5T4 antibody comprising at least one light chain and at least one heavy chain, or a chimeric or humanized fragment thereof, comprising a heavy chain variable region sequence comprising:
(a) an amino acid sequence set forth as SEQ ID NO:19 or 21;
(b) an amino acid sequence that is at least 81% identical to SEQ ID NO:19;
(c) an amino acid sequence that is at least 86% identical to SEQ ID NO:21;
(d) a nucleotide sequence of SEQ ID NO:20 or 83;
(e) a nucleotide sequence that is at least 91% identical to the nucleic acid of SEQ ID NO:20 or SEQ ID NO:83; or
(f) a nucleic acid that specifically hybridizes to the complement of SEQ ID NO:20 or 83 under stringent hybridization conditions.