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KR-20260062948-A - CTLA4/TIGIT Binding Protein and Its Medical Uses

KR20260062948AKR 20260062948 AKR20260062948 AKR 20260062948AKR-20260062948-A

Abstract

The invention provides a CTLA4/TIGIT binding protein and its medical uses. Specifically, it relates to an anti-CTLA4/TIGIT antibody, a method for treating cancer, and pharmaceutical uses.

Inventors

  • 얀 홍
  • 바오 루야오
  • 장 웨이
  • 천 시멍
  • 위안 지민
  • 리아오 청

Assignees

  • 지앙수 헨그루이 파마슈티컬스 컴퍼니 리미티드
  • 상하이 쉥디 파마슈티컬 컴퍼니 리미티드

Dates

Publication Date
20260507
Application Date
20240830
Priority Date
20230831

Claims (16)

  1. In CTLA4/TIGIT binding proteins, A first binding domain that specifically binds to CTLA4, and It includes a second binding domain that specifically binds to TIGIT, and A first binding domain that specifically binds to the CTLA4 comprises a heavy chain variable region (VH1) and a light chain variable region (VL1), wherein VH1 comprises HCDR1, HCDR2, and HCDR3 in the heavy chain variable region of the amino acid sequence represented by SEQ ID NO: 13, and VL1 comprises LCDR1, LCDR2, and LCDR3 in the light chain variable region of the amino acid sequence represented by SEQ ID NO: 14. A second binding domain that specifically binds to the above TIGIT comprises a heavy chain variable region (VH2) and a light chain variable region (VL2), wherein VH2 comprises HCDR1, HCDR2, and HCDR3 in the heavy chain variable region of the amino acid sequence represented by SEQ ID NO: 15, and VL2 comprises LCDR1, LCDR2, and LCDR3 in the light chain variable region of the amino acid sequence represented by SEQ ID NO: 16. The above CDR is defined according to the Kabat, IMGT, Chothia, AbM, or Contact Number System; Preferably, the VH1 comprises HCDR1, HCDR2, and HCDR3 having amino acid sequences represented by SEQ ID NO: 1, 2, and 3, respectively, and the VL1 comprises LCDR1, LCDR2, and LCDR3 having amino acid sequences represented by SEQ ID NO: 4, 5, and 6, respectively; Preferably, the VH2 comprises HCDR1, HCDR2, and HCDR3 having amino acid sequences represented by SEQ ID NO: 7, 8, and 9, respectively, and the VL2 comprises LCDR1, LCDR2, and LCDR3 having amino acid sequences represented by SEQ ID NO: 10, 11, and 12, respectively; More preferably, the CTLA4/TIGIT binding protein is an anti-CTLA4/TIGIT antibody, the CTLA4/TIGIT binding protein.
  2. In paragraph 1, In a first binding domain that specifically binds to the above CTLA4, The above VH1 comprises an amino acid sequence represented by SEQ ID NO: 13 or having at least 90% sequence identity with it; and The above VL1 is a CTLA4/TIGIT binding protein comprising an amino acid sequence represented by SEQ ID NO: 14 or having at least 90% sequence identity with it.
  3. In paragraph 1 or 2, In a second binding domain that specifically binds to the above TIGIT, The above VH2 comprises an amino acid sequence represented by SEQ ID NO: 15 or having at least 90% sequence identity with it; and The above VL2 is a CTLA4/TIGIT binding protein comprising an amino acid sequence represented by SEQ ID NO: 16 or having at least 90% sequence identity with it.
  4. In any one of paragraphs 1 through 3, It further includes the human immunoglobulin Fc region; Preferably, the Fc region is the Fc region of IgG1, IgG2, IgG3, or IgG4; More preferably, the Fc region is the Fc region of human IgG1, and optionally, the Fc region comprises at least one mutation of 239D, 330L, or 332E; CTLA4/TIGIT binding protein characterized by the above mutation being defined according to the Eu number system.
  5. In paragraph 4, The above Fc region includes a first sub-unit and a second sub-unit; Preferably, the first subunit of the Fc region comprises a knob mutation, and the second subunit of the Fc region comprises a hole mutation, a CTLA4/TIGIT binding protein.
  6. In paragraph 5, The first subunit of the above Fc region comprises a mutation at position 366, and the second subunit comprises a mutation at a position selected from positions 366, 368, and 407 or any combination thereof; or The first subunit of the above Fc region contains a mutation at position 354 or 356, and the second subunit contains a mutation at position 349; or The first subunit of the above Fc region includes a mutation at position 354 or 356, and the second subunit includes mutations at positions 349, 366, 368, and 407; Preferably, The first subunit of the above Fc region comprises a 366W mutation, and the second subunit comprises a mutation selected from 366S, 368A, and 407V or any combination thereof; or The first subunit of the above Fc region comprises a 354C or 356C mutation, and the second subunit comprises a 349C mutation; or A CTLA4/TIGIT binding protein, wherein the first subunit of the Fc region comprises the 354C/366W mutation and the second subunit comprises the 349C/366S/368A/407V mutation.
  7. In any one of paragraphs 1 through 6, A CTLA4/TIGIT binding protein further comprising a linker, preferably wherein the linker is denoted as (G m S n ) h or (G m Q n ) h or (GGNGT) h or (YGNGT) h or (EPKSS) h , where m and n are each independently selected from integers 1 to 8, and h is independently selected from integers 1 to 20.
  8. In any one of paragraphs 5 through 7, It includes a first heavy chain, a first light chain, a second heavy chain, and a second light chain; The first heavy chain is sequentially [VH1]-[linker 1]-[Obscurin-O chain]-[linker 3]-[first subunit of the Fc region] from the N-terminus to the C-terminus, and The first light chain is [VL1]-[linker 2]-[Titin-T chain] sequentially from the N-terminus to the C-terminus, and The second heavy chain is sequentially [VH2]-[CH1]-[second subunit of the Fc region] from the N end to the C end, and The second light chain is [VL2]-[CL] sequentially from the N-terminus to the C-terminus; - indicates a peptide bond, The amino acid sequence of the above Obscurin-O chain is denoted by SEQ ID NO: 17, and The amino acid sequence of the above Titin-T chain is denoted by SEQ ID NO: 18, and The above linkers 1, 2, and 3 may be identical or different, and may exist independently or not exist, and Preferably, the amino acid sequences of linker 1 and linker 2 are GGGGS, and linker 3 is absent, a CTLA4/TIGIT binding protein.
  9. In any one of paragraphs 1 through 8, A first heavy chain comprising an amino acid sequence represented by SEQ ID NO: 21 or having at least 90% sequence identity with it, A first light chain comprising an amino acid sequence represented by SEQ ID NO: 22 or having at least 90% sequence identity with it, A second heavy chain comprising an amino acid sequence represented by SEQ ID NO: 23 or having at least 90% sequence identity with it, and A CTLA4/TIGIT binding protein comprising a polypeptide chain combination of a second light chain comprising an amino acid sequence represented by SEQ ID NO: 24 or having at least 90% sequence identity with it.
  10. A polynucleotide encoding a CTLA4/TIGIT binding protein according to any one of claims 1 to 9.
  11. A vector comprising a polynucleotide according to paragraph 10.
  12. A host cell comprising a polynucleotide according to paragraph 10 or a vector according to paragraph 11.
  13. In a pharmaceutical composition, Comprising a CTLA4/TIGIT binding protein according to any one of claims 1 to 9, a polynucleotide according to claim 10, or a vector according to claim 11; Optionally, the pharmaceutical composition further comprises one or more pharmaceutically acceptable excipients, diluents, or adjuvants.
  14. In a method for preparing a CTLA4/TIGIT binding protein, The step of culturing host cells according to claim 12 to express the CTLA4/TIGIT binding protein; Optionally, a method for preparing a CTLA4/TIGIT binding protein, the method further comprising the step of isolating and/or purifying the CTLA4/TIGIT binding protein.
  15. In any one of the following (1)-(3) uses of a CTLA4/TIGIT binding protein according to any one of claims 1 to 9, a polynucleotide according to claim 10, a vector according to claim 11, or a pharmaceutical composition according to claim 13, (1) For the treatment or remission of cancer, or for the manufacture of drugs for the treatment or remission of cancer; (2) For removing or inhibiting Treg cells, or for manufacturing drugs for removing or inhibiting Treg cells; (3) For T cell activation, or for manufacturing drugs for T cell activation; Preferably, the Treg cells are tumor Treg cells; Preferably, the T cells are tumor T cells, and more preferably, tumor CD8+ T cells; Preferably, the cancer is selected from colorectal cancer, non-small cell lung cancer, and breast cancer.
  16. In the treatment or remission of cancer, A method for treating or alleviating cancer, comprising the step of administering to a subject a therapeutically effective amount of a CTLA4/TIGIT binding protein according to any one of claims 1 to 9, a polynucleotide according to claim 10, a vector according to claim 11, or a pharmaceutical composition according to claim 13.

Description

CTLA4/TIGIT Binding Protein and Its Medical Uses The present disclosure relates to CTLA4 and TIGIT binding proteins, such as antiCTLA4/TIGIT antibodies, and cancer treatment using the same. This application claims priority to Chinese patent application number CN202311110063.8 filed on August 31, 2023. In the process of an antitumor immune response, two signals are required for the activation of T cells: the first signal is antigen-specific and is initiated by the recognition of the antigen-peptide-MHC complex on the surface of APC cells by the T cell receptor (TCR) complex; the second signal is a co-stimulatory signal, which requires the participation of a co-stimulatory molecule (e.g., CD28), and when CD28 binds to the ligand CD80/CD86, it further activates the T cells, promotes their maturation and proliferation, and ultimately initiates an immune response (Nat Rev Immunol. 2013 Apr;13(4):227-42.). Regulatory T cells (also called Treg cells) are an important subset of T cells that exert immunosuppressive effects. Treg cells exert immunosuppressive functions primarily through intercellular contact inhibition (e.g., inhibitory receptors interacting with ligands on the surface of target cells) and non-contact inhibition (e.g., secretion of various immunosuppressive cytokines such as IL-10) (Nat Immunol. 2019 Feb;20(2):218-231). CTLA4 protein (also known as cytotoxic T lymphocyte associated antigen-4, CD152) is an immune checkpoint molecule primarily expressed on the surface of activated T cells and Treg cells, and competes with CD28 for CD80 and CD86 ligand binding, with CTLA4 having a higher affinity and exerting immunosuppressive effects. Ipilimumab and Tremelimumab are already commercially approved CTLA4 monoclonal antibodies. These two antibodies can clinically induce characteristic CTLA4 toxicity, including dermatitis, diarrhea, and enteritis (Oncogene. 2015 Oct;34(43):5411-7.; J Transl Med. 2012 Nov 21;10:236.). This suggests that CTLA4 toxicity stems from two aspects: one is the clearance of peripheral Treg cells mediated by ADCC, and the other is the inhibition of CTLA4 signaling in peripheral blood, which disrupts peripheral immune balance and causes immunotoxicity. Therefore, the development of CTLA4 antibodies that reduce side effects without compromising efficacy holds significant clinical value. The TIGIT protein (also known as T cell immunoreceptor with Ig and ITIM domains, or VSIG9) is an immune checkpoint molecule primarily expressed on activated T cells. Ligands of TIGIT include CD155 and CD112. CD155 has a high affinity for TIGIT, while CD112 has a weak affinity. Additionally, CD155 and CD112 are ligands of the co-stimulatory molecule CD226; TIGIT competes with CD226 to bind to CD155 and CD112 on the surface of tumor or APC cells, thereby performing an immunosuppressive function (Trends Immunol. 2017 Jan;38(1):20-28.). TIGIT antibodies possess clinically excellent safety characteristics (Biomedicines. 2021 Sep; 9(9): 1277.). The present disclosure provides an anti-CTLA4/TIGIT antibody of a novel structure, which can selectively target Treg cells containing a co-expressed target protein within the tumor through avidity effects via structural design, and possesses excellent tumor growth inhibition and cytotoxic effects, good therapeutic potential, and high potential clinical safety. The present disclosure provides a CTLA4/TIGIT binding protein and a nucleic acid encoding the same, a vector, a host cell, a pharmaceutical composition, and a method for cancer treatment, Treg cell removal, or T cell enhancement using the same, and related pharmaceutical uses. CTLA4/TIGIT binding protein The present disclosure provides a CTLA4/TIGIT binding protein comprising a first binding domain that specifically binds to CTLA4 and a second binding domain that specifically binds to TIGIT, capable of specifically binding to CTLA4 and TIGIT simultaneously or separately. Regarding the first binding domain that specifically binds to CTLA4: In some embodiments, the first binding domain that specifically binds to CTLA4 among the CTLA4/TIGIT binding proteins comprises a heavy chain variable region (VH1) and a light chain variable region (VL1), wherein VH1 comprises HCDR1, HCDR2, and HCDR3 in the heavy chain variable region of the amino acid sequence represented by SEQ ID NO: 13, and VL1 comprises LCDR1, LCDR2, and LCDR3 in the light chain variable region of the amino acid sequence represented by SEQ ID NO: 14. The above CDR is defined according to the Kabat, IMGT, Chothia, AbM, or Contact number system. In some specific embodiments, the above CDR is defined according to the Kabat number system. In some embodiments, the first binding domain that specifically binds to CTLA4 among the CTLA4/TIGIT binding proteins comprises a heavy chain variable region (VH1) and a light chain variable region (VL1), the VH1 comprises HCDR1, HCDR2, and HCDR3 represented by SEQ ID NO: 1, 2, and 3, respectively, and the VL1 comprises LCDR1,