Methods for treating psoriasis using antibodies that bind to the P40 subunit of IL-12 and/or IL-23

1. A method of treating psoriasis in a subject comprising

administering to the subject a first dose amount of 180 mg to 220 mg of an antibody, or antigen-binding portion thereof, which is capable of binding to the p40 subunit of IL-12 and/or IL-23, at week 0,

administering the same first dose amount of the antibody, or antigen-binding portion thereof, to the subject at week 4, and

administering a second dose amount of 80 mg to 120 mg of the antibody, or antigen-binding portion thereof, to the subject every 4 weeks thereafter, thereby treating psoriasis in the subject.

2. The method of claim 1 , wherein the first dose amount of the antibody, or antigen-binding portion thereof, is 200 mg.

3. The method of claim 1 , wherein the second dose amount of the antibody, or antigen-binding portion thereof, is 100 mg.

4. The method of claim 1 , wherein the first dose amount of the antibody, or antigen-binding portion thereof, is 200 mg and the second dose amount of the antibody, or antigen-binding portion thereof, is 100 mg.

5. The method of claim 1 , wherein the second dose amount is administered to the subject prior to a flare of psoriasis indicated by a loss of Psoriasis Area and Severity Index (PASI) 50 response.

6. The method of claim 1 , wherein the psoriasis is chronic psoriasis.

7. The method of claim 1 , wherein the psoriasis is chronic psoriasis affecting about ≧20% body surface area of the subject.

8. The method of claim 1 , wherein the psoriasis is plaque psoriasis.

9. The method of claim 8 , wherein the plaque psoriasis is moderate to severe plaque psoriasis.

10. The method of claim 1 , wherein the antibody is administered subcutaneously.

11. The method of claim 1 , wherein the subject achieves at least a Physician Global Assessment (PGA) score of 0 or 1 by week 12.

12. The method of claim 1 , wherein the subject achieves at least a Psoriasis Area and Severity Index (PASI) 75 response by week 12.

13. The method of claim 1 , wherein the subject achieves at least a PASI 90 response by week 12.

14. The method of claim 1 , wherein the subject achieves a PASI 100 response by week 12.

15. The method of claim 1 , wherein the antibody is a human antibody.

16. The method of claim 1 , wherein the antibody is ABT-874.

17. The method of claim 1 , wherein the subject achieves a Nail Psoriasis Severity Index (NAPSI) score of about 2.1 or less by week 12.

18. The method of claim 1 , wherein the subject achieves a minimum clinically important difference (MCID) in any one or more health-related quality of life outcomes selected from the group consisting of Dermatology Life Quality Index (DLQI), Total Activity Impairment (TAI), Ps-related (VAS-Ps) pain, psoriatic arthritis-related (VAS-PsA) pain, Short Form 36 Health Survey Mental Component Summary score (MCS) and Short Form 36 Health Survey Mental Component Summary score (PCS) by week 12.