COMPOSITIONS AND METHODS FOR TARGETING CANCER STEM CELLS

1 . A method of treating ovarian cancer comprising:

administering at least one chemotherapeutic agent to a subject, wherein said subject has ovarian cancer, and wherein said at least one chemotherapeutic agent is selected from the group consisting of olaparib, carboplatin, and paclitaxel; and

administering an anti-sialyl Tn antigen (STn) antibody.

2 . The method of claim 1 , wherein said anti-STn antibody is administered after administration of said at least one chemotherapeutic agent.

3 . The method of claim 2 , wherein said anti-STn antibody targets at least one chemotherapy-resistant cell.

4 . The method of claim 3 , wherein said at least one chemotherapy-resistant cell is a cancer stem cell.

5 . The method of claim 1 , wherein said anti-STn antibody comprises:

(a) a heavy chain variable domain (VH) with the amino acid sequence of SEQ ID NO: 1 or the complementarity determining regions (CDRs) thereof; and a light chain variable domain (VL) with the amino acid sequence of SEQ ID NO: 2 or the CDRs thereof; or

(b) a VH with the amino acid sequence of SEQ ID NO: 3 or the CDRs thereof; and a VL with the amino acid sequence of SEQ ID NO: 4 or the CDRs thereof.

6 . The method of claim 5 , wherein said anti-STn antibody is an antibody-drug conjugate.

7 . The method of claim 6 , wherein said anti-STn antibody is conjugated to a cytotoxic agent.

8 . The method of claim 7 , wherein said cytotoxic agent is monomethyl auristatin E (MMAE).

9 . The method of claim 1 , wherein said anti-STn antibody is administered to said subject at a dose of from about 1 mg per kg of subject body weight (mg/kg) to about 10 mg/kg.

10 . The method of claim 1 , wherein STn-positive cells in said subject or in a cancerous tissue in said subject are reduced by from about 20% to about 90%.

11 - 14 . (canceled)

15 . The method of claim 1 , wherein said subject has platinum refractory disease.

16 . A method of treating ovarian cancer comprising:

obtaining a sample from a subject, wherein the subject has or is suspected of having ovarian cancer; and

detecting STn in said sample using an STn-detection antibody, wherein if STn is detected, an anti-STn antibody is administered to said subject.

17 - 21 . (canceled)

22 . The method of claim 16 , wherein said STn-detection antibody comprises:

(a) a VH with the amino acid sequence of SEQ ID NO: 1 and a VL with the amino acid sequence of SEQ ID NO: 2; or

(b) a VH with the amino acid sequence of SEQ ID NO: 3 and a VL with the amino acid sequence of SEQ ID NO: 4.

23 . The method of claim 16 , wherein detecting STn in said sample is carried using at least one method selected from one or more of mass spectrometry, Western blotting, flow cytometry, immunoprecipitation, and enzyme-linked immunosorbent assay (ELISA).

24 . The method of claim 16 , wherein said STn is protein-associated STn.

25 . The method of claim 16 , wherein said STn is associated with an ovarian cancer stem cell-related protein.

26 . The method of claim 25 , wherein said ovarian cancer stem cell-related protein is selected from at least one of MUC1, CD44, CD133, CD117, integrin, Notch, and Hedgehog.

27 - 30 . (canceled)

31 . The method of claim 16 , wherein said anti-STn antibody comprises:

(a) a VH with the amino acid sequence of SEQ ID NO: 1 or the CDRs thereof; and a VL with the amino acid sequence of SEQ ID NO: 2 or the CDRs thereof; or

(b) a VH with the amino acid sequence of SEQ ID NO: 3 or the CDRs thereof; and a VL with the amino acid sequence of SEQ ID NO: 4 or the CDRs thereof.

32 . The method of claim 16 , wherein said anti-STn antibody is administered to said subject at a dose of from about 1 mg/kg to about 10 mg/kg.

33 . The method of claim 16 , wherein STn-positive cells in said subject or in a cancerous tissue in said subject are reduced by from about 20% to about 90%.

34 - 37 . (canceled)

38 . The method of claim 1 , wherein said method of treating ovarian cancer comprises consolidation cancer treatment.

39 - 44 . (canceled)