Treatment of severe psoriasis

Despite the great advances brought about by biologic therapies, treatment of moderate-to-severe psoriasis often represents a challenge. Associated comorbidities may hamper the use of ciclosporin or methotrexate at effective doses, and obesity or heavy weight reduce the therapeutic expectations of systemic treatments, especially with regard to optimal response, which should be the ultimate goal of therapy. Combination therapy has been recognized to be an effective way of improving therapeutic response, and methotrexate at low doses seems especially well suited for combination with biologics, by improving response rates and reducing drug clearance and development of anti-drug antibodies. Secondary lack of response to biologics does occur in a small percentage of patients, and accounts in part for reduced drug survival in dermatology patients. In some cases, especially when the presence of anti-drug antibodies can be demonstrated, switching to another biologic agent in the same class may be effective, but some patients appear to be prone to developing anti-drug antibodies against several agents. In some cases, switching to another class of biologics (e.g. anti-p40 antibodies) can prove to be a very effective alternative, with an excellent safety profile. The present case report illustrates the optimization of therapeutic response to biologics using combination therapy and achieving long-lasting clearance of psoriasis following switching to ustekinumab in a patient who had shown secondary loss of response to several biologics.