The effect of weight on the efficacy of biologic therapy in patients with psoriasis

Background: The prevalence of obesity is rapidly increasing in the United States. Patients with psoriasis, in particular, tend to be above normal weight. Three of the 5 biologics used to treat psoriasis are fixed-dosed treatments: alefacept, etanercept, and adalimumab. Dosing regimens do not account for weight. Objective. We attempted to determine whether the efficacy of the biologics is affected by weight. Methods: We review the existing body of literature, including subgroup analyses, relating to efficacy and weight for infliximab, efalizumab, alefacept, and etanercept. No relevant literature was found for adalimumab. Results: Weight-based dosed medications do not seem to lose efficacy with increasing weight. Both etanercept and alefacept may have compromised efficacy in heavier individuals. Limitations: The data are limited to subgroup analyses and smaller studies, often with no statistical significance reported. Conclusions: Additional studies are warranted, specifically designed to address the issue of obesity and response to therapy of the biologics. Alternative dosing for etanercept and alefacept should be further evaluated in patients above normal weight.