Methods of treating psoriasis by administration of antibodies 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 an antibody, or antigen-binding portion thereof, which is capable of binding to an epitope of the p40 subunit of IL-12 and/or IL-23, for a first extended period of at least 12 weeks, wherein the subject achieves at least a Psoriasis Area and Severity Index (PASI) 75 response by week 12 of the first extended period,

discontinuing administration of the antibody, or antigen-binding portion thereof, for at least 12 weeks following the first extended period of administration of the antibody, or antigen-binding portion thereof, wherein the subject exhibits a loss of response by a decrease in PASI score to less than PASI 50 following discontinuation, and

re-administering to the subject the antibody, or antigen-binding portion thereof, for a second extended period of at least 12 weeks, wherein the subject achieves at least a PASI 50 response by week 12 of the second extended period, thereby treating psoriasis in the subject.

2. The method of claim 1 , wherein the antibody, or antigen-binding portion thereof, is administered or re-administered biweekly.

3. The method of claim 1 , wherein the antibody, or antigen-binding portion thereof, is administered or re-administered weekly.

4. The method of claim 1 , wherein the antibody, or antigen-binding portion thereof, is administered or re-administered in a single dose.

5. The method of claim 1 , wherein the antibody, or antigen-binding portion thereof, is administered or re-administered in a dose of about 200 mg.

6. The method of claim 1 , wherein the antibody, or antigen-binding portion thereof, is administered or re-administered in a dose of about 100 mg.

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

8. The method of claim 1 , wherein the subject achieves at least a PASI 75 response by week 12 of the second extended period.