Advancements in the treatment of psoriasis: role of biologic agents.

OBJECTIVE: To evaluate the role of biologic agents as antipsoriatic therapy.

SUMMARY: Mild psoriasis can generally be managed with topical therapy. Moderate-to-severe psoriasis has traditionally been treated with systemic therapies such as cyclosporine, methotrexate, retinoids, and phototherapy (ultraviolet B, psoralen plus ultraviolet A). The treatments for moderate-to-severe psoriasis often do not meet patient and physician expectations because of significant side effects (e.g., organ toxicity, skin cancer), lack of durable efficacy, and inconvenient administration schedules (e.g., daily dosing, multiple weekly exposures). The recognition of psoriasis as a T-cell.mediated disease has led to the development of biologic agents that more specifically target key steps in the pathologic process. A review of the literature was conducted to identify randomized controlled trials that have been published on the efficacy, safety, and quality-of-life effects of both approved and investigational biologics for the treatment of psoriasis. The first 2 biologic agents for the treatment of moderate-to-severe chronic plaque psoriasis were approved by the U.S. Food and Drug Administration (FDA) in 2003, alefacept in January and efalizumab in October. Both agents have demonstrated favorable safety profiles in clinical trials and significant benefits on patient quality of life. Head-to-head trials are lacking, but in placebo controlled trials, similar percentages of patients appear to respond to each of these 2 drugs. An advantage of alefacept is that it has been shown in clinical trials to provide durable off-treatment efficacy (approximately 7 months). Efalizumab has a relatively quick onset of antipsoriatic effect, but it needs to be administered once weekly continuously to maintain symptom control. Etanercept (approved by the FDA for treating moderate-to-severe plaque psoriasis in May 2004) and infliximab (not FDA-approved for psoriasis treatment) have also shown promise in randomized controlled trials, although less data are available on these agents. Case reports and pilot studies suggest that other biologics under investigation may also prove useful for the treatment of psoriasis. Patient populations that may particularly benefit from biologic therapy are discussed.

CONCLUSION: Biologic agents appear to offer a safe and effective alternative to conventional systemic therapies and phototherapy for the treatment of moderate-to-severe chronic plaque psoriasis. The biologics appear to be safer than traditional therapies, although long-term safety data still need to be established.