The tumor necrosis factor (TNF) blocker adalimumab has been approved by the Food and Drug Administration for inhibiting structural joint damage and improving physical function in patients with psoriatic arthritis, based on study results.
The psoriatic arthritis indication in the product label now says that it is indicated for reducing the signs and symptoms of active arthritis, inhibiting the progression of structural damage, and improving physical function in patients with psoriatic arthritis. Adalimumab, marketed as Humira by Abbott Laboratories, was approved for treating psoriatic arthritis in October 2005.
The latest approval is based on an extension of a trial of patients with moderate to severe psoriatic arthritis, who had inadequate responses to NSAID treatment, comparing 40 mg of adalimumab every other week with placebo in 313 patients, according to a statement issued by Abbott. After 24 weeks, 285 patients continued in an open-label extension of the trial.
At 24 weeks, those on adalimumab had significantly less joint damage than did those on placebo, as determined by the modified total Sharp score, based on x-rays at baseline, 24 weeks, and 48 weeks. Inhibition of radiographic progression on x-rays was significantly greater among those on adalimumab at 24 weeks, and was maintained at 48 weeks.
The physical function indication is based on the significant improvements in physical function documented in the Health Assessment Questionnaire Disability Index (HAQ-DI), and physical component of the Short Form-36 Health Status Survey (SF-36). Those on adalimumab had significantly greater improvements in the HAQ-DI score, with mean decreases of 47% at 12 weeks and 49% at 24 weeks, compared with mean decreases of 1% and 3%, respectively, among those on placebo. Improvements in physical function, as seen on the HAQ-DI, were maintained for up to 84 weeks, according to the revised label. Those on adalimumab also had significantly greater improvements in the physical component of the SF-36 score, compared with those on placebo at weeks 12 and 24.