ACR: Actemra Found Safe and Effective In Systemic Juvenile Idiopathic Arthritis

WASHINGTON, Nov. 12 -- The novel agent Actemra (tocilizumab), an investigational a humanized monoclonal antibody is safe and effective in children with systemic juvenile idiopathic arthritis, a Japanese researcher said here.

In a prospective, randomized phase III trial, 90% of children had an improvement of 50% over 12 weeks of therapy with Actemra, which blocks the interleukin-6 receptor, according to Shumpei Yokota, M.D., of Yokohama City University School of Medicine.

"It works," Dr. Yokota said before he presented data from the study at the American College of Rheumatology meeting.

He noted that the drug is now being tested in various indications in adults as well as in children but has so far been approved only for Castleman's Disease and only in Japan.

"This disease is so serious and destructive in children, and we have no choices for treatment except systemic corticosteroids and immunosuppression."

About 7% of cases are fatal because the disease makes a transition to macrophage activation syndrome, which Dr. Yokota described as a "cytokine storm."

About one in 10 children with arthritis will have the systemic idiopathic disease, which is characterized by recurrent fever accompanied by rash. Eventually, as in other forms, the joints are involved.

Dr. Yokota and colleagues enrolled 56 children with inadequate response to systemic corticosteroids and active disease, defined as C-reactive protein (CRP) serum levels greater than or equal to 1.5 mg/dL.

They were all treated initially, in a six-week open-label induction phase, with 8 mg/kg of Actemra every two weeks.

In most patients, Dr. Yokota said, the persistent fever was immediately normalized and CRP levels fell to the normal range.

Forty-three patients both responded to the treatment and agreed to join the 12-week double-blind part of the trial, Dr. Yokota said, adding that 20 were randomized to Actemra and 23 to placebo.

Four patients in the Actemra arm withdrew compared with 19 of those getting placebo - a difference that was statistically significant at P

The value of the drug to the patients and their parents can be measured, Dr. Yokota said, by their persistence. Getting to Yokohama for the study was "time-consuming and money-consuming," he said.

"But they come because the disease is so improved," he said.