Therapeutic method and medicament for HTLV-1 associated myelopathy

1. A therapeutic method, comprising reducing spontaneous cell proliferation and human T cell leukemia virus type-1 (HTLV-1) virus-infected cells in a HTLV-1 associated myelopathy (HAM) patient, said method comprising administering an anti-human CCchemokine receptor 4 (CCR4) antibody to the HAM patient,

wherein said anti-human CCR4 antibody is selected from the group consisting of

(i) an anti-human CCR4 antibody that binds to an epitope included at positions 2-29 from the N-terminus of CCR4 protein, and

(ii) an antibody that includes heavy chain complementarity determining regions (CDRs) 1-3 of SEQ ID NOS: 1-3, respectively, and light chain CDRs 1-3 of SEQ ID NOS: 4-6, respectively, and

wherein the HTLV-1 virus-infected cells are CCR4 + T cells.

2. The therapeutic method according to claim 1 , wherein the administering an anti-human CCR4 antibody reduces an amount of HTLV-1 proviral DNA in the HAM patient.

3. The therapeutic method according to claim 1 , wherein the administering an anti-human CCR4 antibody reduces an expression level of a cytokine produced by the HTLV-1 virus-infected cells.

4. The therapeutic method according to claim 3 , wherein the cytokine is any one selected from the group consisting of interferon γ, tumor necrosis factor α, interleukin (IL)-2, IL-6, IL-10 and IL-17.

5. The therapeutic method according to claim 1 , comprising further administering one or more drugs selected from the group consisting of an immunosuppressant and an anti-viral agent.

6. The therapeutic method according to claim 5 , wherein the immunosuppressant is any one selected from the group consisting of prednisolone, methylprednisolone, dexamethasone, betamethasone, azathioprine, cyclosporine, tacrolimus, a JAK inhibitor, and a NFκB inhibitor.

7. The therapeutic method according to claim 1 , comprising further administering an immunosuppressant at a 1-10 mg dose.

8. The method of claim 1 , wherein the anti-human CCR4 antibody further comprises a heavy chain variable region of SEQ ID NO. 7 and a light chain variable region of SEQ ID NO. 8.

9. The therapeutic method according to claim 1 further comprising:

administering an immunosuppressant.

10. The therapeutic method according to claim 9 , wherein the immunosuppressant is an adrenocorticosteroid.

11. The therapeutic method according to claim 9 , wherein the immunosuppressant is any one of an adrenocorticosteroid selected from the group consisting of prednisolone, methylprednisolone, dexamethasone and betamethasone.

12. The therapeutic method according to claim 9 , wherein the immunosuppressant is prednisolone.

13. A method selected from the following (i)-(iv):

(i) a method for reducing spontaneous cell proliferation and human T cell leukemia virus type-1 (HTLV-1) virus-infected cells of a HTLV-1-associated myelopathy (HAM) patient, comprising administering an anti-human CCR4 antibody to the HAM patient;

(ii) a method for reducing spontaneous cell proliferation and a HTLV-1 proviral DNA amount of a HAM patient, comprising administering an anti-human CCR4 antibody to the HAM patient; and

(iii) a method for inhibiting spontaneous cell proliferation and a production of a cytokine that is produced by the HTLV-1 virus-infected cell of a HAM patient, comprising administering an anti-human CCR4 antibody to the HAM patient,

wherein said anti-human CCR4 antibody is selected from the group consisting of

(a) an anti-human CCR4 antibody that binds to an epitope included at positions 2-29 from the N-terminus of CCR4 protein, and

(b) an antibody that includes heavy chain complementarity determining regions (CDRs) 1-3 of SEQ ID NOS: 1-3, respectively, and light chain CDRs 1-3 of SEQ ID NOS: 4-6, respectively.

14. The method of claim 13 , wherein the anti-human CCR4 antibody further comprises a heavy chain variable region of SEQ ID NO. 7 and a light chain variable region of SEQ ID NO. 8.