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EP-4736958-A2 - ANTI-5T4 ANTIBODIES AND USES THEREOF

EP4736958A2EP 4736958 A2EP4736958 A2EP 4736958A2EP-4736958-A2

Abstract

This disclosure provides anti-5T4 antibodies, variants thereof and humanized versions. The newly disclosed antibodies exhibited high affinity to the 5T4 protein and can be used to treat cancers.

Inventors

  • LIU, FANG
  • GONG, Wenci
  • CAI, ZHIJIAN
  • YANG, LIU
  • GAO, SHAN
  • JIANG, WENQING
  • FANG, LEI

Assignees

  • Lepu Biopharma Co., Ltd.

Dates

Publication Date
20260506
Application Date
20230221

Claims (20)

  1. An antibody or antigen-binding fragment thereof which has specificity to the human 5T4 oncofetal trophoblast glycoprotein (5T4) protein and comprises a heavy chain variable region (VH) comprising a VH CDR1, a VH CDR2 and a VH CDR3, and a light chain variable region (VL) comprising a VL CDR1, a VL CDR2, and a VL CDR3, wherein the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 54, 55 (or any one of 60-63, or 266 or 267), 56, 57, 58 and 59; SEQ ID NO: 123, 124 or 129, 125, 126, 127 and 128; or SEQ ID NO: 160, 161 or 166, 162, 163, 164 and 165.
  2. The antibody or antigen-binding fragment thereof of claim 1, wherein: the VH CDR1 comprises the amino acid sequence of SEQ ID NO: 54; the VH CDR2 comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 55, 60-63 and 266-267; the VH CDR3 comprises the amino acid sequence of SEQ ID NO: 56; the VL CDR1 comprises the amino acid sequence of SEQ ID NO: 57; the VL CDR2 comprises the amino acid sequence of SEQ ID NO: 58; and the VL CDR3 comprises the amino acid sequence of SEQ ID NO: 59.
  3. The antibody or antigen-binding fragment thereof of claim 2, wherein the VH comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 3, 215-221 and 248-256, and the VL comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 4 and 222-226.
  4. The antibody or antigen-binding fragment thereof of claim 1, wherein: the VH CDR1 comprises the amino acid sequence of SEQ ID NO: 123; the VH CDR2 comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 124 and 129; the VH CDR3 comprises the amino acid sequence of SEQ ID NO: 125; the VL CDR1 comprises the amino acid sequence of SEQ ID NO: 126; the VL CDR2 comprises the amino acid sequence of SEQ ID NO: 127; and the VL CDR3 comprises the amino acid sequence of SEQ ID NO: 128.
  5. The antibody or antigen-binding fragment thereof of claim 4, wherein the VH comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 23, 236-241 and 259-261, and the VL comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 24 and 242-247.
  6. The antibody or antigen-binding fragment thereof of claim 1, wherein: the VH CDR1 comprises the amino acid sequence of SEQ ID NO: 160; the VH CDR2 comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 161 and 166; the VH CDR3 comprises the amino acid sequence of SEQ ID NO: 162; the VL CDR1 comprises the amino acid sequence of SEQ ID NO: 163; the VL CDR2 comprises the amino acid sequence of SEQ ID NO: 164; and the VL CDR3 comprises the amino acid sequence of SEQ ID NO: 165.
  7. The antibody or antigen-binding fragment thereof of claim 6, wherein the VH comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 35, and the VL comprises an amino acid sequence selected from the group consisting of SEQ ID NO: 36.
  8. The antibody or fragment thereof of any one of claims 1-7, wherein the antibody or fragment thereof is a bivalent Fab antibody, or a fragment selected from the group consisting of F(ab')2, F(ab)2, Fab', Fab, Fv, and scFv.
  9. An antibody-drug conjugate comprising an antibody or fragment thereof of any one of claims 1-8 conjugated to a drug moiety.
  10. The antibody-drug conjugate of claim 9, wherein the drug moiety is a cytotoxic or cytostatic agent.
  11. The antibody-drug conjugate of claim 10, wherein the drug moiety is a maytansinoid, an auristatin, or a macrocyclic ketone analogue.
  12. The antibody-drug conjugate of claim 11, wherein the drug moiety comprises monomethyl auristatin E (MMAE) or monomethyl auristatin F (MMAF).
  13. The antibody-drug conjugate of any one of claims 9-12, wherein the drug moiety is attached to the antibody or fragment thereof through a linker that is hydrolyzable under acidic conditions.
  14. A multispecific antibody comprising an antigen-binding fragment of any one of claims 1-8 and one or more antibody or antigen-binding fragment having binding specificity to a target antigen that is not 5T4.
  15. A chimeric antigen receptor (CAR) comprising an antigen-binding fragment of any one of claims 1-8, a transmembrane domain, a costimulatory domain, and a CD3ξ intracellular domain.
  16. One or more polynucleotide(s) encoding the antibody or antigen-binding fragment thereof of any one of claims 1-8 or the CAR of claim 15.
  17. The polynucleotide(s) of claim 16, which is one or more mRNA.
  18. The polynucleotide(s) of claim 17, wherein the mRNA is chemically modified.
  19. A cell comprising the polynucleotide(s) of any one of claims 16-18.
  20. A composition comprising the antibody or antigen-binding fragment thereof of any one of claims 1-8, the antibody-drug conjugate of any one claims 9-13, the multispecific antibody of claim 14, the CAR of claim 15, the polynucleotide(s) of any one of claims 16-18, or the cell of claim 19, and a pharmaceutically acceptable carrier.

Description

BACKGROUD 5T4 (also known as trophoblast glycoprotein, TPBG; 5T4 oncofetal trophoblast glycoprotein; and Wnt-activated inhibitory factor 1, WAIF1) is a vertebrate-specific, single-pass transmembrane protein first identified in human placental tissues. 5T4 contains a highly glycosylated, rigid core, comprising eight leucine-rich repeats (LRRs) in the extracellular domain, a transmembrane helix and a cytoplasmic region. The cytoplasmic PDZ-binding motif Ser-Asp-Val of 5T4 has been reported to interact with the PDZ domain of TIP-2/GIPC, a cytoplasmic protein that associates with vesicles located near the cell membrane. Further downstream mechanisms of signal transduction remain unknown. 5T4 has also been found to inhibit the Wnt/β-catenin signaling pathway, a key pathway in embryonic development and a major target for anticancer therapeutics. 5T4 is rarely expressed in normal adult tissues, but is present at high levels in placenta and in most common tumors, typically more than 80% of carcinomas of the kidney, breast, colon, prostate, and ovary. Thus, 5T4 has the characteristics of an oncofetal antigen, highlighting it as a possible candidate for use as a diagnostic marker or target for cancer treatment. SUMMARY The present disclosure, in various embodiments, provides antibodies and antigen-binding fragments specific to the human 5T4 protein. Experimental testing shows that these newly identified antibodies can bind to the human 5T4 protein potently and specifically. Contrary to naptumomab, which is a fusion protein containing the Fab-fragment targeting 5T4 and has been evaluated in clinical trials, these newly identifies antibodies can bind to the cynomolgus monkey 5T4 protein with a comparable potency, as well. In accordance with one embodiment of the present disclosure, provided is an antibody or antigen-binding fragment thereof which has specificity to the human 5T4 oncofetal trophoblast glycoprotein (5T4) protein and comprises a heavy chain variable region (VH) comprising a VH CDR1, a VH CDR2 and a VH CDR3, and a light chain variable region (VL) comprising a VL CDR1, a VL CDR2, and a VL CDR3. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 41, 42 (or any one of 47-53), 43, 44, 45 and 46 (or 264 or 265). In some embodiments, the VH CDR1 comprises the amino acid sequence of SEQ ID NO: 41; the VH CDR2 comprises the amino acid sequence of SEQ ID NO: 42; the VH CDR3 comprises the amino acid sequence of SEQ ID NO: 43; the VL CDR1 comprises the amino acid sequence of SEQ ID NO: 44; the VL CDR2 comprises the amino acid sequence of SEQ ID NO: 45; and the VL CDR3 comprises the amino acid sequence of SEQ ID NO: 264 or 265. In some embodiments, the VH comprises the amino acid sequence of SEQ ID NO: 197, and the VL comprises the amino acid sequence of SEQ ID NO: 262 or 263. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 54, 55 (or any one of 60-63, or 266 or 267), 56, 57, 58 and 59. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 64-69. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 70, 71 or 76, 72, 73, 74 or 75. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 77-82. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 83-88. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 89-94. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 95, 96 (or any one of 101-104), 97, 98, 99 and 100. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 105-110. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 111-116. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 117-122. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 123, 124 or 129, 125, 126, 127 and 128. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the amino acid sequences of SEQ ID NO: 130-135. In some embodiments, the VH CDR1, VH CDR2, VH CDR3, VL CDR1, VL CDR2 and VL CDR3 comprise, respectively, the a