Granted Patent B2

US 12,594,350 · App. 15/478,596 · Granted Apr 7, 2026

Inventors: Heather Dawn Agnew (Culver City, CA); Bert Tsunyin Lai (Culver City, CA)

Assignee: Regeneron Pharmaceuticals, Inc.

A61K51/08C07K7/06C07K14/001C07K14/70517G01N33/534G01N33/56972G01N33/68G01N2333/70517

Abstract

Claims (130)

1 . A method of producing a synthetic capture agent that specifically binds to CD8 comprising

(a) selecting a first ligand that binds to a first synthetic epitope of CD8 by screening a peptide library for epitope-templated in situ click reaction of the first synthetic epitope and a peptide in the peptide library that comprises a proparglyglycine;

(b) selecting a second ligand that binds to a second synthetic epitope of CD8 by screening a peptide library for epitope-templated in situ click reaction of the second synthetic epitope and a peptide in the peptide library that comprises a proparglyglycine; and

(c) covalently joining a linker to the first ligand and the second ligand, thereby producing the synthetic capture agent that binds to CD8,

wherein the first synthetic epitope comprises the sequence SQFRVSPLD[Az4]TWNLGETVELKSQ (SEQ ID NO: 54) and the second synthetic epitope comprises the sequence FLLYLSQNKP[Az4]AAEGLDTQR (SEQ ID NO: 55).

2 . The method of claim 1 , wherein the length of the linker is the distance between a first native epitope of CD8 bound by the first ligand and a second native epitope of CD8 bound by the second ligand.

3 . The method of claim 1 , wherein the length of the linker is from 4.4 Å to 39.6 Å.

4 . The method of claim 3 , wherein the length of the linker is from 26.4 Å to 39.6 Å.

5 . The method of claim 4 , wherein the length of the linker is 28.2 Å.

6 . The method of claim 1 , wherein the linker comprises one or more repeat units of ethylene glycol.

7 . The method of claim 6 , wherein the linker comprises PEG 1 , PEG 2 , PEG 3 , PEG 4 , PEG 5 , PEG 6 , PEG 7 , or PEG 8 .

8 . The method of claim 1 , wherein the linker comprises an amino acid or a peptide.

9 . A synthetic capture agent that binds to CD8, wherein the synthetic capture agent comprises a first ligand that is cyclic and 5-9 amino acids in length having affinity for a first epitope on CD8, a second ligand that is cyclic and 5-9 amino acids in length having affinity for a second epitope on CD8, and a linker covalently connecting the first ligand to the second ligand,

wherein the first ligand comprises an amino acid sequence chosen from:

(a) 

(SEQ ID NO: 6)

HGSYG;

(b) 

(SEQ ID NO: 7)

KRLGA;

(c) 

(SEQ ID NO: 8)

AKYRG;

(d) 

(SEQ ID NO: 9)

hallw;

(e) 

(SEQ ID NO: 10)

lrGvw;

(f) 

(SEQ ID NO: 11)

vashf;

(g) 

(SEQ ID NO: 12)

nGnvh;

(h) 

(SEQ ID NO: 13)

wplrf;

(i) 

(SEQ ID NO: 14)

rwfnv;

(j) 

(SEQ ID NO: 15)

havwh;

(k) 

(SEQ ID NO: 16)

wvplw;

(l) 

(SEQ ID NO: 17)

ffrly; and

(m) 

(SEQ ID NO: 18)

wvvGf,

 and

wherein the second ligand comprises an amino acid sequence chosen from:

(a) 

(SEQ ID NO: 19)

AGDSW;

(b) 

(SEQ ID NO: 20)

HVRHG;

(c) 

(SEQ ID NO: 21)

HGRGH;

(d) 

(SEQ ID NO: 22)

THPTT;

(e) 

(SEQ ID NO: 23)

FAGYH;

(f) 

(SEQ ID NO: 24)

WTEHG;

(g) 

(SEQ ID NO: 25)

PWTHG;

(h) 

(SEQ ID NO: 26)

TNDFD;

(i) 

(SEQ ID NO: 27)

LFPFD;

(j) 

(SEQ ID NO: 28)

slrfG;

(k) 

(SEQ ID NO: 29)

yfrGs;

(l) 

(SEQ ID NO: 30)

wnwvG;

(m) 

(SEQ ID NO: 31)

vawlG;

(n) 

(SEQ ID NO: 32)

fhvhG;

(o) 

(SEQ ID NO: 33)

wvsnv;

(p) 

(SEQ ID NO: 34)

wsvnv;

(q) 

(SEQ ID NO: 35)

lnshG;

(r) 

(SEQ ID NO: 36)

yGGvr;

(s) 

(SEQ ID NO: 37)

nsvhG;

(t) 

(SEQ ID NO: 38)

ttvhG;

(u) 

(SEQ ID NO: 39)

fdvGh;

(v) 

(SEQ ID NO: 40)

rhGwk; and

(w) 

(SEQ ID NO: 49)

hGrGh.

10 . The synthetic capture agent of claim 9 , wherein the first ligand comprises wlprf (SEQ ID NO: 13) and the second ligand comprises HGRGH (SEQ ID NO: 21).

11 . The synthetic capture agent of claim 9 , wherein the first ligand comprises AKYRG (SEQ ID NO: 8) and the second ligand comprises HGRGH (SEQ ID NO: 21).

12 . The synthetic capture agent of claim 9 , wherein the first ligand comprises AKYRG (SEQ ID NO: 8) and the second ligand comprises PWTHG (SEQ ID NO: 25).

13 . A method for detecting CD8 in a biological sample, comprising

contacting the biological sample with one or more synthetic capture agents of claim 9 , wherein the one or more synthetic capture agents are labeled with a detectable moiety, and

detecting the detectable moiety when the one or more synthetic capture agents bind to CD8 in the biological sample.

Assignments (2)

Continuity (2)

References Cited (217)