The U.S. Food and Drug Administration (FDA) in 2011 approved the biologic drug tocilizumab, or Actemra, for systemic juvenile idiopathic arthritis in children older than age 2.
One or two out of every 1,000 children have juvenile idiopathic arthritis, and about 10 percent of those children get systemic juvenile idiopathic arthritis, or SJIA. It is distinguished from other forms of juvenile arthritis by serious inflammation in the bloodstream that can affect internal organs and cause high fevers and rashes.
An FDA spokesperson says Actemra is the first therapy approved specifically to treat systemic juvenile idiopathic arthritis. Other drugs approved for juvenile arthritis – like Enbrel, Humira and Orencia – have been used to treat SJIA, but they don’t always do enough to mitigate the effects of SJIA.
Actemra is a relative newcomer to disease-modifying arthritis drugs; in early 2010 it was approved to treat adults with moderate to severe rheumatoid arthritis who did not respond adequately to TNF-alpha blockers like Enbrel and Humira. Instead of targeting the inflammatory cytokine TNF-alpha, Actemra is the first drug to block the inflammatory cytokine IL-6, or interleukin-6, which also plays a key role in driving the inflammatory process.
“The immune system in the body uses certain molecules, like TNF, interleukin-1 and interleukin-6, to create inflammation,” says FDA spokesperson Morgan Liscinsky. “Not all inflammatory diseases have inflammation that is driven by the same process, so they may have different responsiveness to treatment with agents that block the specific inflammatory molecules.”
Actemra’s approval for children comes after a multi-center study on 112 SJIA patients between the ages of 2 and 17. Every two weeks, half the participants were given Actemra and the other half placebo. Eighty-five percent of those who got Actemra had at least a 30 percent improvement in their symptoms over the previous week, compared with 24 percent of patients in the placebo group.
Actemra is administered as an infusion. The most common side effects that occurred in at least 5 percent of patients were upper respiratory tract infections, colds, headaches, sore throat, congestion and diarrhea. Three participants also developed the potentially deadly condition known as macrophage activation syndrome, a complication of systemic inflammatory disorders in children that involves overactive immune cells. But FDA officials say the incidents weren’t higher than what is generally seen among this specific patient population.
Barbara Adams, MD, director of pediatric rheumatology at the University of Michigan Health System in Ann Arbor, says she regularly sees the effects of SJIA on children and welcomes anything new that might help them.
“I think that any new medication for childhood arthritis, particularly this type of potentially lethal childhood arthritis, is good news,” Dr. Adams says.
The FDA recommends that children taking Actemra are monitored with regular blood tests to make sure there are no adverse side effects related to liver function, blood components or cholesterol.
“When a new drug comes out we know what it’s done in the test but we don’t know what it will do day-to-day,” Dr. Adams says. “We need the experience of seeing more kids use it. We need to understand as pediatric rheumatologists how to use it in the most effective way and in which children it will be most effective.”