Psoriasis is a chronic inflammatory, immune-mediated,
genetic disease predominantly affecting the skin and associated with significant patient morbidity. Conventional topical and systemic treatment options are numerous and generally effective, with varying degrees of success and rapidity of action. However, recurrence of disease is inevitable.
Biologic agents that target pathogenic T cells have been shown to be effective in patients with moderate to severe
psoriasis, with the remittive effects of
alefacept encouraging in a small proportion of patients.
Efalizumab recently was withdrawn from the US market after 5 years of use because of 3 cases of
progressive multifocal leukoencephalopathy (PML), a serious life-threatening
infection. The
tumor necrosis factor alpha (
TNF-alpha) inhibitors
etanercept,
infliximab, and
adalimumab have demonstrated notable initial and maintenance efficacy in the treatment of moderate to severe
psoriasis but require monitoring because of safety concerns, including risk for
infections. A new class of
biologic agents, anti-IL-12 and
IL-23 antibodies (
ustekinumab and ABT-874), shows significant promise for the treatment of moderate to severe
psoriasis. However, as new agents in medicine, more evidence is required regarding long-term safety. Despite the efficacy of these
biologic agents, which have revolutionized the
therapy for moderate to severe
psoriasis, complete clearances are not always obtained and relapses occur in a proportion of patients. To maintain better control of the disease, many physicians and patients are choosing combination or adjunctive
therapies to augment the results seen with
biologic agents. However, to date, there are no well-controlled studies demonstrating safety and/or efficacy of
biologic agents in combination with other
therapies. Prospective trials of this sort are therefore needed to better understand the potential risks and benefits of such approaches.