Placebo will be administered.

A PASI 90 response represents participants who achieved at least a 90 percent improvement from baseline in the PASI score. The PASI is a system used for assessing and grading the severity of psoriatic lesions. In the PASI system, the body is divided into 4 regions: the head, trunk, upper extremities, and lower extremities. Each of these areas were assessed separately for the percentage of the area involved, which translates to a numeric score that ranges from 0 to 6, and for erythema, induration, and scaling, which are each rated on a scale of 0 to 4. The PASI produces a numeric score that can range from 0 to 72. A higher score indicates more severe disease.

A PASI 100 response represents participants who achieved at least a 100 percent improvement from baseline in the PASI score. The PASI is a system used for assessing and grading the severity of psoriatic lesions. In the PASI system, the body is divided into 4 regions: the head, trunk, upper extremities, and lower extremities. Each of these areas were assessed separately for the percentage of the area involved, which translates to a numeric score that ranges from 0 to 6, and for erythema, induration, and scaling, which are each rated on a scale of 0 to 4. The PASI produces a numeric score that can range from 0 to 72. A higher score indicates more severe disease.

The ACR 20 responders are participants with an improvement of >= 20% from baseline in both the tender and swollen joint count and in at least 3 of the 5 assessments (patient's assessment of pain VAS, patient's global assessment of disease activity [arthritis, VAS] scale, Physician's global assessment of disease activity VAS scale, Health Assessment Questionnaire and C-reactive protein).

The ACR 70 responders are participants with an improvement of >= 70% from baseline in both the tender and swollen joint count and in at least 3 of the 5 assessments (patient's assessment of pain VAS, patient's global assessment of disease activity [arthritis, VAS] scale, Physician's global assessment of disease activity VAS scale, health assessment questionnaire and C-reactive protein).

The HAQ-DI score consists of questions referring to 8 categories: dressing/grooming, arising, eating, walking, hygiene, reach, grip, and common daily activities. Responses in each functional area are scored from 0 to 3 (0=no difficulty and 3=inability to perform a task in that area). Overall score was computed as the sum of domain scores and divided by the number of domains answered. Total possible score range 0-3 where 0 = least difficulty and 3 = extreme difficulty.

SF-36 is a standardized survey evaluating 8 aspects of functional health and wellbeing: physical and social functioning, physical and emotional role limitations, bodily pain, general health, vitality, mental health. The score for a domain was an average of the individual question scores, which were scaled 0 to 100 (100=highest level of functioning). Score from physical function, role physical, bodily pain, and general health domains were averaged to calculate PCS. Total score range for PCS was 0-100 (100=highest level of physical functioning).

Participants with change from baseline in the laboratory parameters (hematology and serum chemistry) will be reported.