Objective: Adalimumab, a fully human, anti-tumor necrosis factor monoclonal antibody, was evaluated for its safety and efficacy compared with placebo in the treatment of active psoriatic arthritis (PsA).
Methods: Patients with moderately to severely active PsA and a history of inadequate response to nonsteroidal antiinflammatory drugs were randomized to receive 40 mg adalimumab or placebo subcutaneously every other week for 24 weeks. Study visits were at baseline, weeks 2 and 4, and every 4 weeks thereafter. The primary efficacy end points were the American College of Rheumatology 20% improvement (ACR20) response at week 12 and the change in the modified total Sharp score of structural damage at week 24. Secondary end points were measures of joint disease, disability, and quality of life in all patients, as well as the severity of skin disease in those patients with psoriasis involving at least 3% of body surface area.
Results: At week 12, 58% of the adalimumab-treated patients (87 of 151) achieved an ACR20 response, compared with 14% of the placebo-treated patients (23 of 162) (P < 0.001). At week 24, similar ACR20 response rates were maintained and the mean change in the modified total Sharp score was -0.2 in patients receiving adalimumab and 1.0 in those receiving placebo (P < 0.001). Among the 69 adalimumab-treated patients evaluated with the Psoriasis Area and Severity Index (PASI), 59% achieved a 75% PASI improvement response at 24 weeks, compared with 1% of the 69 placebo-treated patients evaluated (P < 0.001). Disability and quality of life measures were also significantly improved with adalimumab treatment compared with placebo. Adalimumab was generally safe and well-tolerated.
Conclusion: Adalimumab significantly improved joint and skin manifestations, inhibited structural changes on radiographs, lessened disability due to joint damage, and improved quality of life in patients with moderately to severely active PsA.