METHODS AND SORTILIN BINDING CONJUGATE COMPOUNDS FOR TARGETING CANCER STEM CELLS

1 . A method for treating a cancer comprising Sortilin-expressing cancer stem cells (CSCs) in a subject comprising administering to the subject an effective amount of a conjugate compound or a pharmaceutically acceptable salt thereof, wherein the conjugate compound has the formula of A-(B) n , wherein

A is a peptide compound of 30 residues or less comprising an amino acid sequence having at least 60% sequence identity to one of the sequences of formulas (I)-(XIII):

(I)

(SEQ ID NO: 1)

X 1 X 2 X 3 X 4 X 5 GVX 6 AKAGVX 7 NX 8 FKSESY

(II)

(SEQ ID NO: 2)

(X 9 ) n GVX 10 AKAGVX 11 NX 12 FKSESY

(III)

(SEQ ID NO: 3)

YKX 13 LRRX 14 APRWDX 15 PLRDPALRX 16 X 17 L

(IV)

(SEQ ID NO: 4)

YKX 18 LRR(X 19 ) N PLRDPALRX 20 X 21 L

(V)

(SEQ ID NO: 5)

IKLSGGVQAKAGVINMDKSESM

(VI)

(SEQ ID NO: 6)

IKLSGGVQAKAGVINMFKSESY

(VII)

(SEQ ID NO: 7)

IKLSGGVQAKAGVINMFKSESYK

(VIII)

(SEQ ID NO: 8)

GVQAKAGVINMFKSESY

(IX)

(SEQ ID NO: 9)

GVRAKAGVRNMFKSESY

(X)

(SEQ ID NO: 10)

GVRAKAGVRN(Nle)FKSESY

(XI)

(SEQ ID NO: 11)

YKSLRRKAPRWDAPLRDPALRQLL

(XII)

(SEQ ID NO: 12)

YKSLRRKAPRWDAYLRDPALRQLL

(XIII)

(SEQ ID NO: 13)

YKSLRRKAPRWDAYLRDPALRPLL

wherein

X 1 , X 2 , X 3 , X 4 , X 5 , X 6 , X 7 , X 8 , X 9 , X 10 , X 11 , X 12 , X 13 , X 14 , X 15 , X 18 and X 19 are independently chosen from any amino acid;

X 16 , X 17 , X 20 and X 21 are independently chosen from Q, P, Y, I and L;

n is 0, 1, 2, 3, 4 or 5;

when X 9 is present more than once, each of said X 9 is independently chosen from any amino acid;

when X 19 is present more than once, each of said X 9 is independently chosen from any amino acid,

optionally the peptide compound is cyclic,

B is at least one antitumor agent, wherein B is connected to A directly or via a linker.

2 . The method of claim 1 , wherein the peptide compound comprises an amino acid sequence having at least 90% sequence identity to one of the sequences of formulas (I)-(XIII).

3 . The method of claim 1 or 2 , wherein the peptide compound comprises one of the sequences of formulas (I)-(XIII), and further comprises 1 to 3 additional amino acids at its amino- and/or carboxy-terminal end.

4 . The method of claim 3 , wherein the peptide compound comprises a cysteine residue at its amino- and/or carboxy-terminal end.

5 . The method of claim 1 , wherein the peptide compound is represented by formula (I) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 1 or 2.

6 . The method of claim 1 , wherein the peptide compound is represented by formula (III) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 3 or 4.

7 . The method of claim 1 , wherein the peptide compound is represented by formula (V) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 5.

8 . The method of claim 1 , wherein the peptide compound is represented by formula (VI) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 6.

9 . The method of claim 1 , wherein the peptide compound is represented by formula (VII) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 7.

10 . The method of claim 1 , wherein the peptide compound is represented by formula (VIII) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 8.

11 . The method of claim 1 , wherein the peptide compound is represented by formula (IX) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 9.

12 . The method of claim 1 , wherein the peptide compound is represented by formula (X) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 10.

13 . The method of claim 1 , wherein the peptide compound is represented by formula (XI) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 11.

14 . The method of claim 1 , wherein the peptide compound is represented by formula (XII) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 12.

15 . The method of claim 1 , wherein the peptide compound is represented by formula (XIII) and has an amino acid sequence consisting of the amino acid sequence of SEQ ID NO: 13.

16 . The method of any one of claims 1 to 15 , wherein the peptide compound comprises at least one modifying group at its amino- and/or carboxy-terminal end.

17 . The method of claim 16 , wherein the at least one modifying group is acetyl or succinyl.

18 . The method of claim 1 , wherein the peptide compound is represented by Formula (XXXVIII), (XXXIX), (XL), (XLI) or (XLII):

(XXXVIII)

(SEQ ID NO: 14)

Acetyl-GVRAKAGVRNMFKSESY

(XXXIX)

(SEQ ID NO: 15)

Acetyl-GVRAKAGVRN(Nle)FKSESY

(XL)

(SEQ ID NO: 16)

Acetyl-YKSLRRKAPRWDAPLRDPALRQLL

(XLI)

(SEQ ID NO: 17)

Acetyl-YKSLRRKAPRWDAYLRDPALRQLL

(XLII)

(SEQ ID NO: 18)

Acetyl-YKSLRRKAPRWDAYLRDPALRPLL.

19 . The method of any one of claims 1 to 18 , wherein B is connected to A at a free amine of said peptide compound, at an N-terminal position of said peptide compound, at a free —SH of said peptide compound, and/or at a free carboxyl of said peptide compound.

20 . The method of any one of claims 1 to 19 , wherein B is connected to A via a linker.

21 . The method of any one of claims 1 to 20 , wherein the conjugate is represented by formula (LIII) or (LIV):

(LIII)

(SEQ ID NO: 23)

GVRAK(Z 1 )AGVRN(Nle)FK(Z 2 )SESY;

(LIV)

(SEQ ID NO: 24)

Acetyl-GVRAK(Z 1 )AGVRN(Nle)FK(Z 2 )SESY;

wherein Z 1 and Z 2 are each independently an antitumor agent attached to the lysine (K) residues.

22 . The method of any one of claims 1 to 21 , wherein the antitumor agent is a radionuclide or a chemotherapeutic agent.

23 . The method of claim 22 , wherein the chemotherapeutic agent is a taxane.

24 . The method of claim 23 , wherein the chemotherapeutic agent is docetaxel.

25 . A method for preventing or treating a cancer relapse or recurrence associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject, the method comprising administering to the subject an effective amount of the conjugate or salt thereof defined in any one of claims 1 to 24 .

26 . A method for treating a poor prognosis cancer associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject, the method comprising administering to the subject an effective amount of the conjugate or salt thereof defined in any one of claims 1 to 24 .

27 . A method for treating an unresectable, chemotherapy- and radiotherapy-resistant cancer associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject, the method comprising administering to the subject an effective amount of the conjugate or salt thereof defined in any one of claims 1 to 24 .

28 . The method of any one of claims 1 to 27 , wherein the CSCs express at least one multidrug resistance (MDR) protein.

29 . The method of claim 28 , wherein the CSCs express MDR1 and/or ABCB5.

30 . The method of any one of claims 1 to 29 , wherein the cancer is breast cancer, urogenital cancer, pancreatic cancer, lung cancer, thyroid cancer, kidney cancer, gastrointestinal tract cancer, neuroendocrine tumors, neuroblastoma, skin cancer, brain cancer and leukemia.

31 . The method of claim 30 , wherein the urogenital cancer is ovarian cancer, prostate cancer, endometrial cancer or testis cancer.

32 . The method of claim 30 , wherein the breast cancer is invasive ductal carcinoma (IDC) or triple negative breast cancer (TNBC).

33 . The method of claim 30 , wherein the kidney cancer is renal cell carcinoma (RCC).

34 . The method of claim 30 , wherein the gastrointestinal tract cancer is colorectal cancer.

35 . The method of claim 30 , wherein the skin cancer is melanoma.

36 . The method of claim 30 , wherein the brain cancer is glioma.

37 . The method of claim 30 , wherein the leukemia is B cell Chronic Lymphocytic Leukemia (B-CLL).

38 . The method of claim 30 , wherein the cancer is breast cancer, ovarian cancer or pancreatic cancer.

39 . The method of any one of claims 1 to 38 , wherein the administration of the conjugate or salt thereof inhibits migration of the CSCs in the subject.

40 . The method of any one of claims 1 to 39 , wherein the method further comprises administering one or more additional active agents or therapies to the subject.

41 . The method of claim 40 , where the one or more additional active agents or therapies comprise radiotherapy, surgery, chemotherapeutic agents, immunotherapies, checkpoint inhibitors, and/or cell-based therapies.

42 . Use of the conjugate or salt thereof defined in any one of claims 1 to 24 for the preparation of a medicament for treating a cancer comprising Sortilin-expressing cancer stem cells (CSCs) in a subject.

43 . Use of the conjugate or salt thereof defined in any one of claims 1 to 24 for the preparation of a medicament for preventing or treating a cancer relapse or recurrence associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject.

44 . Use of the conjugate or salt thereof defined in any one of claims 1 to 24 for the preparation of a medicament for treating a poor prognosis cancer associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject.

45 . Use of the conjugate or salt thereof defined in any one of claims 1 to 24 for the preparation of a medicament for treating an unresectable, chemotherapy- and radiotherapy-resistant cancer associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject.

46 . The use of any one of claims 42 to 45 , wherein the CSCs express at least one multidrug resistance (MDR) protein.

47 . The use of claim 46 , wherein the CSCs express MDR1 and/or ABCB5.

48 . The use of any one of claims 42 to 47 , wherein the cancer is breast cancer, urogenital cancer, pancreatic cancer, lung cancer, thyroid cancer, kidney cancer, gastrointestinal tract cancer, neuroendocrine tumors, neuroblastoma, skin cancer, brain cancer and leukemia.

49 . The use of claim 48 , wherein the urogenital cancer is ovarian cancer, prostate cancer, endometrial cancer or testis cancer.

50 . The use of claim 48 , wherein the breast cancer is invasive ductal carcinoma (IDC) or triple negative breast cancer (TNBC).

51 . The use of claim 48 , wherein the kidney cancer is renal cell carcinoma (RCC).

52 . The use of claim 48 , wherein the gastrointestinal tract cancer is colorectal cancer.

53 . The use of claim 48 , wherein the skin cancer is melanoma.

54 . The use of claim 48 , wherein the brain cancer is glioma.

55 . The use of claim 48 , wherein the leukemia is B cell Chronic Lymphocytic Leukemia (B-CLL).

56 . The use of claim 48 , wherein the cancer is breast cancer, ovarian cancer or pancreatic cancer.

57 . The use of any one of claims 42 to 56 , wherein the medicament inhibits migration of the CSCs in the subject.

58 . The use of any one of claims 42 to 57 , wherein the medicament is for use with one or more additional active agents or therapies.

59 . The use of claim 58 , where the one or more additional active agents or therapies comprise radiotherapy, surgery, chemotherapeutic agents, immunotherapies, checkpoint inhibitors, and/or cell-based therapies.

60 . The conjugate or salt thereof as defined in any one of claims 1 to 24 for use in treating a cancer comprising Sortilin-expressing cancer stem cells (CSCs) in a subject.

61 . The conjugate or salt thereof as defined in any one of claims 1 to 24 for use in preventing or treating a cancer relapse or recurrence associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject.

62 . The conjugate or salt thereof as defined in any one of claims 1 to 24 for use in treating a poor prognosis cancer associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject.

63 . The conjugate or salt thereof as defined in any one of claims 1 to 24 for use in treating an unresectable, chemotherapy- and radiotherapy-resistant cancer associated with the presence of Sortilin-expressing cancer stem cells (CSCs) in a subject.

64 . The conjugate or salt thereof for use according to any one of claims 60 to 63 , wherein the CSCs express at least one multidrug resistance (MDR) protein.

65 . The conjugate or salt thereof for use according to claim 64 , wherein the CSCs express MDR1 and/or ABCB5.

66 . The conjugate or salt thereof for use according to any one of claims 61 to 65 , wherein the cancer is breast cancer, urogenital cancer, pancreatic cancer, lung cancer, thyroid cancer, kidney cancer, gastrointestinal tract cancer, neuroendocrine tumors, neuroblastoma, skin cancer, brain cancer and leukemia.

67 . The conjugate or salt thereof for use according to claim 66 , wherein the urogenital cancer is ovarian cancer, prostate cancer, endometrial cancer or testis cancer.

68 . The conjugate or salt thereof for use according to claim 66 , wherein the breast cancer is invasive ductal carcinoma (IDC) or triple negative breast cancer (TNBC).

69 . The conjugate or salt thereof for use according to claim 66 , wherein the kidney cancer is renal cell carcinoma (RCC).

70 . The conjugate or salt thereof for use according to claim 66 , wherein the gastrointestinal tract cancer is colorectal cancer.

71 . The conjugate or salt thereof for use according to claim 66 , wherein the skin cancer is melanoma.

72 . The conjugate or salt thereof for use according to claim 66 , wherein the brain cancer is glioma.

73 . The conjugate or salt thereof for use according to claim 66 , wherein the leukemia is B cell Chronic Lymphocytic Leukemia (B-CLL).

74 . The conjugate or salt thereof for use according to claim 66 , wherein the cancer is breast cancer, ovarian cancer or pancreatic cancer.

75 . The conjugate or salt thereof for use according to any one of claims 60 to 74 , wherein the conjugate or salt thereof inhibits migration of the CSCs in the subject.

76 . The conjugate or salt thereof for use according to any one of claims 60 to 75 , wherein the conjugate or salt thereof is for use with one or more additional active agents or therapies.

77 . The conjugate or salt thereof according to claim 76 , where the one or more additional active agents or therapies comprise radiotherapy, surgery, chemotherapeutic agents, immunotherapies, checkpoint inhibitors, and/or cell-based therapies.