Psoriasis is a psychologically and physically disabling disease that affects 1-3% of the US and
European population; about a quarter of patients have moderate to severe disease.
Currently available treatments for psoriasis (e.g. ciclosporin, methotrexate) are either incompletely effective or are associated with toxic effects.
The cytokine tumour necrosis factor alpha (TNF-a) is thought to have a role in the pathogenesis of psoriasis. Alice Gottlieb and colleagues from UMDNJ-Robert Wood Johnson Medical School, New Jersey, USA, therefore conducted a double-blind, randomized trial to assess the clinical benefit and safety of infliximab (a TNF-a blocker).
33 patients with moderate-to-severe psoriasis were enrolled in the study. They were randomly assigned intravenous placebo, infliximab 5 mg/kg, or infliximab 10 mg/kg at baseline, and after two and six weeks.
|Proportion of psoriasis patients responding to treatment:|
10 mg/kg infliximab: 91%
5 mg/kg infliximab: 82%
Patients were assessed after 10 weeks for the primary endpoint (an appropriate score on the physician's global assessment [PGA]).
9 of 11 (82%) patients in the infliximab 5 mg/kg group responded to treatment (good, excellent, or clear rating on PGA). 2 of 11 (18%) in the placebo group and 10 of 11 (91%) patients in the infliximab 10 mg/kg group responded.
The average time for treatment response was 4 weeks for patients in both infliximab groups.
There were no serious adverse events, and infliximab was well tolerated.
Alice Gottlieb comments, "Further studies are required in this target population to firmly establish the safety and efficacy of infliximab, in the treatment of moderate to severe psoriasis, especially for long-term treatment of this chronic disease.
"However, the clinical response to anti-TNF-a monotherapy in this trial suggests that, among the many cytokines and growth factors overexpressed in psoriatic plaques, TNF-a has a pivotal role in the pathogenesis of psoriasis."