# US 2023/0056815 A1 · Antibodies to feline mcdonough sarcoma (fms)-like tyrosine kinase 3 receptor ligand (flt3l) and uses thereof for treating autoimmune and inflammatory diseases

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- Number: US 2023/0056815 A1
- Document ID: US20230056815A1
- Status: Published application
- Kind: A1
- Application number: 17/814,075
- Filed: 2022-07-21
- Published: 2023-02-23
- Earliest claimed: 2018-02-14
- Assignees: Viela Bio, Inc.
- Applicants: Vielo Bio, Inc.
- Inventors: Anna HANSEN; Xiao Xiaodong; Peter Pavlik; Yan Chen; Catherine Rachel Ettinger
- Web page: https://patentgrep.com/patent/US20230056815A1

## CPC

- C07K 16/243: {Colony Stimulating Factors}
- C07K 16/40: against enzymes
- A61P 37/02: Immunomodulators
- C07K 16/00: Immunoglobulins [IG], e.g. monoclonal or polyclonal antibodies
- A61K 2039/505: {comprising antibodies}
- C07K 2317/24: containing regions, domains or residues from different species, e.g. chimeric, humanized or veneered
- C07K 2317/52: Constant or Fc region; Isotype
- C07K 2317/565: Complementarity determining region [CDR]
- C07K 2317/567: Framework region [FR]
- C07K 2317/76: Antagonist effect on antigen, e.g. neutralization or inhibition of binding
- 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)
- A61P: SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS OR MEDICINAL PREPARATIONS
- 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)

## Abstract

Provided herein are anti-FLT3L antibodies and methods of using the antibodies to treat autoimmune and other inflammatory diseases.

## Claims

### Claim at position 1

-39. (canceled)

### Claim 40

A method of reducing binding of Feline McDonough Sarcoma (FMS)-like Tyrosine Kinase 3 Receptor Ligand (FLT3L) by FLT3 comprising contacting FLT3L with an antibody or antigen-binding fragment thereof that binds to FLT3L, wherein the antibody or antigen-binding fragment thereof comprises a set of Complementarity-Determining Regions (CDRs): HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 29, 30, 31, 32, 33, and 34, respectively.

### Claim 41 (depends on 40)

The method of claim 40, wherein the FLT3L is expressed on a cell surface.

### Claim 42 (depends on 40)

The method of claim 40, wherein the FLT3L is expressed as a secreted homodimer.

### Claim 43 (depends on 40)

The method of claim 40, wherein the contacting is in vivo.

### Claim 44 (depends on 40)

The method of claim 40, wherein the contacting is in vitro.

### Claim 45 (depends on 43)

The method of claim 43, wherein the contacting is in vivo in a subject with an inflammatory disease or autoimmune disease.

### Claim 46 (depends on 45)

The method of claim 45, wherein the subject has an inflammatory disease selected from the group consisting of: type 1 diabetes, type 2 diabetes, chronic kidney disease, nephropathy, atherosclerosis, Alzheimer's disease, cancer, heart disease, hypertension, anemia, pericarditis, and renal osteodystrophy.

### Claim 47 (depends on 45)

The method of claim 45, wherein the autoimmune disease is selected from the group consisting of: Sjogren's Syndrome, nephritis, myositis, systemic lupus erythematosus, multiple sclerosis, uveitis, psoriasis, and rheumatoid arthritis.

### Claim 48 (depends on 40)

The method of claim 40, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable region (VH) and light chain variable region (VL), wherein the VH and VL regions comprise an amino acid sequence having at least 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 1 and SEQ ID NO: 2, respectively.

### Claim 49 (depends on 48)

The method of claim 48, wherein the VH and VL comprise the amino acid sequence of: SEQ ID NO: 1 and SEQ ID NO: 2, respectively.

### Claim 50 (depends on 40)

The method of claim 40, comprising the antibody, wherein the antibody is a monoclonal antibody, a recombinant antibody, a human antibody, a humanized antibody, or a chimeric antibody.

### Claim 51 (depends on 40)

The method of claim 40, comprising the antigen-binding fragment thereof, wherein the antigen-binding fragment thereof is selected from the group consisting of: Fab, F(ab′)2, Fv, single-chain Fvs (scFv), single-chain antibody, disulfide-linked Fvs (sdFv), fragments comprising either a VL or VH domain (Fd), fragments produced by a Fab expression library, and combinations thereof.

### Claim 52 (depends on 50)

The method of claim 50, wherein the antibody is a monoclonal antibody.

### Claim 53 (depends on 40)

The method of claim 40, wherein the antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:61 and a light chain comprising the amino acid sequence of SEQ ID NO:62.

### Claim 54

A method of treatment comprising administering an effective amount of a pharmaceutical composition comprising a Feline McDonough Sarcoma (FMS)-like Tyrosine Kinase 3 Receptor Ligand (FLT3L) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprises a set of Complementarity-Determining Regions (CDRs): HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 29, 30, 31, 32, 33, and 34, respectively.

### Claim 55 (depends on 54)

The method of claim 54, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable region (VH) and light chain variable region (VL), wherein the VH and VL regions comprise an amino acid sequence having at least 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 1 and SEQ ID NO: 2, respectively.

### Claim 56 (depends on 55)

The method of claim 55, wherein the VH and VL comprise the amino acid sequence of: SEQ ID NO: 1 and SEQ ID NO: 2, respectively.

### Claim 57 (depends on 54)

The method of claim 54, wherein the antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO:61 and a light chain comprising the amino acid sequence of SEQ ID NO: 62.

### Claim 58 (depends on 54)

The method of claim 54, wherein the treatment is of an autoimmune disease.

### Claim 59 (depends on 58)

The method of claim 58, wherein the treatment is of an inflammatory disease.

### Claim 60 (depends on 58)

The method of claim 58, wherein the autoimmune disease is selected from the group consisting of: Sjogren's Syndrome, nephritis, myositis, systemic lupus erythematosus, multiple sclerosis, uveitis, psoriasis, and rheumatoid arthritis.

### Claim 61 (depends on 59)

The method of claim 59, wherein the inflammatory disease is selected from the group consisting of: type 1 diabetes, type 2 diabetes, chronic kidney disease, nephropathy, atherosclerosis, Alzheimer's disease, cancer, heart disease, hypertension, anemia, pericarditis, renal osteodystrophy, and any complication thereof.

### Claim 62

A method of treating an autoimmune disease comprising administering an effective amount of a pharmaceutical composition comprising a Feline McDonough Sarcoma (FMS)-like Tyrosine Kinase 3 Receptor Ligand (FLT3L) antibody or antigen-binding fragment thereof to a subject in need thereof, wherein the antibody or antigen-binding fragment thereof comprises a set of Complementarity-Determining Regions (CDRs): HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3, wherein the HCDR1, HCDR2, HCDR3, LCDR1, LCDR2, and LCDR3 comprise the amino acid sequences of SEQ ID NOs: 29, 30, 31, 32, 33, and 34, respectively, and wherein the autoimmune disease is selected from the group consisting of: multiple sclerosis, uveitis, psoriasis, and rheumatoid arthritis.

### Claim 63 (depends on 62)

The method of claim 62, wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable region (VH) and light chain variable region (VL), wherein the VH and VL regions comprise an amino acid sequence having at least 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 1 and SEQ ID NO: 2, respectively.

### Claim 64 (depends on 63)

The method of claim 63, wherein the VH and VL comprise the amino acid sequence of: SEQ ID NO: 1 and SEQ ID NO: 2, respectively.

### Claim 65 (depends on 62)

The method of claim 62, wherein the antibody comprises a heavy chain comprising the amino acid sequence of SEQ ID NO: 61 and a light chain comprising the amino acid sequence of SEQ ID NO: 62.