A FDA panel recommended that the psoriasis drug Enbrel should be approved for the treatment of the pediatric patients who are diagnosed with moderate-to severe forms of this illness.

Enbrel, produced by Amgen, is a soluble tumor necrosis factor (TNF) receptor fusion protein that binds TNF-α. Enbrel was first approved by the FDA in 1998 for the treatment of adult rheumatoid arthritis, and is currently approved for the treatment of rheumatoid arthritis, polyarticular-course juvenile idiopathic arthritis, psoriatic arthritis, ankylosing spondylitis, and adult plaque psoriasis. Currently in the US, there are no approved systemic drugs for the treatment of psoriasis in children or adolescents.

Plaque psoriasis is a chronic T-lymphocyte mediated inflammatory skin disease characterized by erythematous plaques with silvery-white scales. Psoriasis plaques are characterized by keratinocyte hyperproliferation, vascular endothelial proliferation and inflammatory cell infiltration. The most common form of psoriasis in children is plaque psoriasis.

The mainstay of treatment for most psoriasis patients regardless of age is topical therapy. Emollients are used to decrease scaling and itching, and may be sufficient in mild cases. The most commonly used treatment is topical corticosteroids.

There is no approved systemic therapy for the treatment of plaque psoriasis in the pediatric population. Systemic therapy for treating childhood psoriasis is generally reserved for the most severe plaque psoriasis recalcitrant to topical therapies. The National Center for Health Statistics of the Centers for Disease Control and

Prevention estimated in 1996 that the prevalence of the disease in children under the age of 18 was 0.32%. Of affected children, 2% of cases begin in the first two years of life and 10% are diagnosed before the age of 10 years.

Amgen has submitted to the panel the results from its Phase III study of Enbrel. The study was made on 211 patients lasting a total of 48 weeks. The study initially randomized patients to placebo or etanercept at 0.8 mg/kg weekly by subcutaneous injection for 12 weeks. All participants then received open-label etanercept for an additional 24 weeks.

Among the young patients treated with the drug for 12 weeks, 57 percent showed that at least a 75 percent improvement in disease severity scored compared with only 11 percent of those receiving a placebo.

The patients encountered mild or moderate side effects. The most common were upper tract infections, headache, nasopharyngitis, injection-site reactions, streptococcal pharyngitis, cough, vomiting and skin papilloma. There were four serious events including three infections and one ovarian cyst, which required removal. All patients recovered without permanent problems.

However, the FDA panel expressed its concerns that Enbrel, although it appears to be an effective therapy, will increase risks of malignancy and serious infections like tuberculosis.

Seven members has voted for the approval, while five expressed their disagreement. In fact, earlier this month, FDA announced it will review Enbrel, along with other several TNF blockers, because they might lead to cancer in children and young adults.

Besides Enbrel, the drugs under investigation are infliximab (Remicade, Johnson & Johnson) and adalimumab (Humira, Abbott Laboratories).