# US 2026/0109779 A1 · Bispecific antibodies against ceacam5 and cd3

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- Number: US 2026/0109779 A1
- Document ID: US20260109779A1
- Status: Published application
- Kind: A1
- Application number: 19/331,063
- Filed: 2025-09-17
- Published: 2026-04-23
- Earliest claimed: 2019-09-18
- Assignees: Lamkap Bio Alpha AG
- Applicants: LamKap Bio Alpha AG
- Inventors: Klaus STREIN; Sara MAJOCCHI
- Web page: https://patentgrep.com/patent/US20260109779A1

## CPC

- C07K 16/3007: {Carcino-embryonic Antigens}
- A61K 39/001129: {Molecules with a "CD" designation not provided for elsewhere}
- A61K 39/001182: {Carcinoembryonic antigen [CEA]}
- A61P 35/00: Antineoplastic agents
- C07K 16/2803: {against the immunoglobulin superfamily}
- C07K 16/2809: {against the T-cell receptor (TcR)-CD3 complex}
- A61K 2039/505: {comprising antibodies}
- A61K 2039/507: {Comprising a combination of two or more separate antibodies}
- A61K 2039/545: {characterised by the dose, timing or administration schedule}
- C07K 2317/31: multispecific
- C07K 2317/33: Crossreactivity, e.g. for species or epitope, or lack of said crossreactivity
- C07K 2317/34: Identification of a linear epitope shorter than 20 amino acid residues or of a conformational epitope defined by amino acid residues
- C07K 2317/35: Valency
- C07K 2317/565: Complementarity determining region [CDR]
- C07K 2317/622: Single chain antibody (scFv)
- C07K 2317/73: Inducing cell death, e.g. apoptosis, necrosis or inhibition of cell proliferation
- C07K 2317/92: Affinity (KD), association rate (Ka), dissociation rate (Kd) or EC50 value
- C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00)
- A61K: PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES (devices or methods specially adapted for bringing pharmaceutical products into particular physical or administering forms A61J3/00; chemical aspects of, or use of materials for deodorisation of air, for disinfection or sterilisation, or for bandages, dressings, absorbent pads or surgical articles A61L; soap compositions C11D)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS

## Abstract

The present invention relates to bispecific antibodies which bind to human carcinoembryonic antigen CEACAM5 (CEA) and human CD3ε. In addition, the present invention relates to polynucleotides encoding such bispecific antibodies and vectors and host cells comprising such polynucleotides. The invention further relates to methods for selecting and producing such antibodies and to methods of using such antibodies in the treatment of diseases.

## Claims

### Claim at position 1

-34. (canceled)

### Claim 35

A method of treating cancer, comprising administering an effective amount of a bispecific antibody comprising a first binding part, specifically binding to human CEACAM5, and a second binding part, specifically binding to human CD3ε to a subject in need thereof, wherein:
a) the first binding part comprises a heavy chain variable region (VH), which comprises a CDRH1 of SEQ ID NO: 2, a CDRH2 of SEQ ID NO: 3 and a CDRH3 of SEQ ID NO: 4,
b) the first binding part comprises a light chain variable region (VL) comprising
b1) a CDRL1 of SEQ ID NO: 32, CDRL2 of SEQ ID NO: 33, and CDRL3 of SEQ ID NO: 34,
b2) a CDRL1 of SEQ ID NO: 81, CDRL2 of SEQ ID NO: 82, and CDRL3 of SEQ ID NO: 83,
b3) a CDRL1 of SEQ ID NO: 84, CDRL2 of SEQ ID NO: 85, and CDRL3 of SEQ ID NO: 86,
b4) a CDRL1 of SEQ ID NO: 87, CDRL2 of SEQ ID NO: 88, and CDRL3 of SEQ ID NO: 89,
b5) a CDRL1 of SEQ ID NO: 90, CDRL2 of SEQ ID NO: 91, and CDRL3 of SEQ ID NO: 92,
b6) a CDRL1 of SEQ ID NO: 93, CDRL2 of SEQ ID NO: 94, and CDRL3 of SEQ ID NO: 95,
b7) a CDRL 1 of SEQ ID NO: 96, CDRL2 of SEQ ID NO: 97, and CDRL3 of SEQ ID NO: 98,
b8) a CDRL1 of SEQ ID NO: 99, CDRL2 of SEQ ID NO: 100, and CDRL3 of SEQ ID NO: 101,
b9) a CDRL1 of SEQ ID NO: 102, CDRL2 of SEQ ID NO: 103, and CDRL3 of SEQ ID NO: 104,
b10) a CDRL1 of SEQ ID NO: 105, CDRL2 of SEQ ID NO: 106, and CDRL3 of SEQ ID NO: 107,
b11) a CDRL1 of SEQ ID NO: 108, CDRL2 of SEQ ID NO: 109, and CDRL3 of SEQ ID NO: 110, or
b12) a CDRL1 of SEQ ID NO: 111, CDRL2 of SEQ ID NO: 112, and CDRL3 of SEQ ID NO: 113,
c) the second binding part comprises a VH comprising a CDRH1 of SEQ ID NO: 2, CDRH2 of SEQ ID NO: 3 and CDRH3 of SEQ ID NO: 4, and
d) the second binding part comprises a VL comprising a CDRL1 of SEQ ID NO: 18, CDRL2 of SEQ ID NO: 19, and CDRL3 of SEQ ID NO: 20 to a subject in need thereof.

### Claim 36 (depends on 35)

The method of claim 35, wherein the bispecific antibody:
a) binds to MKN-45 cells with an EC50 value of 0.5 nM to 50 nM;
b) kills MKN-45, HPAF-II, or LS174T cells in an assay containing human PBMC in a concentration dependent manner with an EC50 value of 0.01 to 10 nM;
c) bind to CEACAM5 expressing PEAK cells, but does not cross react with CEACAM8 expressing PEAK cells;
d) the EC50 value for killing in a TDCC assay using LS174T tumor cells as target cells is not increased by more than a factor 5 in the presence of 1 μg/mL of sCEA relative to the EC50 in the absence of sCEA; and/or
e) inhibits tumor growth in a HPAF-II model by 25% or more compared to the vehicle control group.

### Claim at position 4

-40. (canceled)

### Claim 41 (depends on 35)

The method of claim 35, wherein the bispecific antibody competes with an anti-CEA antibody comprising as VL and VH the VL and VH of sequences SEQ ID NOs: 48 and 49.

### Claim 42 (depends on 35)

The method of claim 35, wherein the bispecific antibody comprises a Fc domain and comprises the amino acid substitutions L234A, L235A and P329A in the Fc domain, as numbered according to Kabat EU index numbering.

### Claim 43 (depends on 35)

The method of claim 35, wherein the subject is a human.

### Claim 44 (depends on 35)

The method of claim 35, wherein the subject has esophageal cancer, pancreatic adenocarcinoma, head and neck carcinoma, uterine cancer, bladder cancer, colorectal cancer, non-small cell lung cancer (NSCLC), gastric cancer, pancreatic cancer or breast cancer.

### Claim 45

(canceled)

### Claim 46

(canceled)

### Claim 47 (depends on 35)

The method of claim 35, wherein the bispecific antibody is administered as a monotherapy.

### Claim 48 (depends on 47)

The method of claim 47, wherein the bispecific antibody is administered as a treatment of CEA-expressing solid tumors.

### Claim 49 (depends on 35)

The method of claim 35, wherein the bispecific antibody is administered in combination with a bispecific anti-CEA×CD47 antibody in simultaneous, separate, or sequential combination.

### Claim 50 (depends on 49)

The method of claim 49, wherein the bispecific antibody is administered in an alternating manner with a bispecific anti-CEA×CD47 antibody with intervals of 6 to 15 days between administration of the bispecific antibody of the invention and the bispecific anti-CEA×CD47 antibody.

### Claim 51 (depends on 35)

The method of claim 35, wherein the bispecific antibody is administered in combination with a PD-1 axis antagonist in simultaneous, separate, or sequential combination.

### Claim 52 (depends on 35)

The method of claim 35, wherein the bispecific antibody is administered in a dose between 0.1 to 100 mg/kg of body weight per day or per week.

### Claim 53 (depends on 35)

The method of claim 35, wherein the bispecific antibody is administered in a dose between 1 to 20 mg/kg.

### Claim 54 (depends on 52)

The method of claim 52, wherein the bispecific antibody is administered in a divided dose.

### Claim 55 (depends on 52)

The method of claim 52, wherein the bispecific antibody is administered by continuous infusion.

### Claim 56 (depends on 49)

The method of claim 49, wherein the bispecific anti-CEA×CD47 antibody is administered to a patient in doses ranging from 0.1 to 100 mg/kg of body weight per day or per week in single or divided doses, or by continuous infusion.

### Claim 57 (depends on 51)

The method of claim 51, wherein the PD-1 axis antagonist is administered to a patient in doses ranging from 0.1 to 100 mg/kg of body weight per day or per week in single or divided doses, or by continuous infusion.

### Claim at position 22

-63. (canceled)

### Claim 64 (depends on 51)

The method of claim 51, wherein the PD-1 axis antagonist is selected from the group consisting of pembrolizumab, nivolumab, pidilizumab, and lambrolizumabmab.

### Claim 65 (depends on 64)

The method of claim 64, wherein the PD-1 axis antagonist is pembrolizumab.

### Claim 66 (depends on 51)

The method of claim 51, wherein the bispecific antibody and the PD-1 axis antagonist are in separate pharmaceutical compositions.