TUESDAY, July 15 (HealthDay News) -- Children suffering from juvenile arthritis who haven't had luck with other treatments may benefit from a drug called Orencia (abatacept).

The conclusions follow from a randomized trial of 122 patients aged 6 to 17 from 45 centers in Europe and in the United States. All participants had a history of juvenile idiopathic arthritis and had at least five joints with active disease. All had tried and failed at least one previous drug.

Participants were randomly assigned to receive 10 milligrams per kilogram of Orencia at 28-day intervals for six months or until the arthritis flared up, or a placebo given on the same schedule.

Just over half (53 percent) of patients on the placebo and 20 percent of those on Orencia experienced an exacerbation of their condition. The odds of a flare-up in patients on Orencia were only 31 percent of that for patients on the placebo. Side effects were similar.

According to the Arthritis Foundation, juvenile idiopathic arthritis is a family of diseases involving chronic joint inflammation. Current drugs seem to fall short of what's needed, with up to 85 percent of children expected to relapse.

The study was conducted by researchers at the Istituto G Gaslini Pediatria II, Largo Gaslini, in Genova, Italy, and was published online in The Lancet.

An accompanying commentary questioned the design of the study, suggesting that it might overestimate the benefit of the drug while understating its side effects.

More information

The Arthritis Foundation has more on juvenile arthritis.