Bristol-Myers Squibb Company has announced results regarding the efficacy and safety of Orencia (abatacept) from the open-label phase of an ongoing investigational study in children with juvenile idiopathic arthritis (JIA) who have had an inadequate response to one or more disease-modifying anti- rheumatic drugs (DMARDs), such as methotrexate (MTX) or tumour necrosis factor (TNF) antagonists.

The results demonstrated that, after a study protocol- mandated withdrawal period of up to six months, the re-introduction of Orencia was associated with a re-establishment of clinical improvement as measured by the American College of Rheumatology's Paediatric (ACR Pedi) criteria for improvement in children with JIA. The data will be presented at the Annual Congress of the European League Against Rheumatism.

"Children with JIA can have long periods of inactive disease and clinical remission, which makes it important to study the efficacy and safety of re- starting a treatment after a withdrawal period," said Edward H Giannini, M.Sc., Dr P H , Professor of Paediatrics, Division of Rheumatology, Cincinnati Children's Hospital Medical Centre, OH, co-principal investigator of the study. "The results of this investigational study suggest that, in these children with JIA who had disease flares while taking placebo during the mandated withdrawal phase, resuming therapy with Orencia was associated with a re-establishment of clinical improvement."

The study, designed to assess the efficacy, safety and tolerability of Orencia in children and adolescents (ages 6-17 years) with JIA, consisted of three periods, a four-month open-label lead-in treatment period in which all participants received Orencia and both a clinical response and safety were assessed (Period A), a six-month randomised double-blind withdrawal phase where responders received either Orencia (abatacept) or placebo (Period B) and time to disease flare and safety were assessed, and an open-label phase designed to assess efficacy and long-term safety (Period C). Children in periods A and B remained on a stable dose of MTX and children in Period C were permitted one of three DMARDs in addition to Orencia.

Fifty-nine children randomised to placebo in Period B participated in Period C to receive open label treatment with Orencia. Thirty-three of them experienced a flare while 26 did not.

Everyone in Period C received 10 mg/kg of Orencia approximately every 28 days. Of the 33 children who received placebo and experienced disease flares during the Period B protocol-mandated withdrawal phase of up to six months, 80 per cent had an ACR Pedi 30 response, 70 per cent had an ACR Pedi 50 response, 50 per cent had an ACR Pedi 70 Response and 27 per cent had an ACR Pedi 90 response after re-introduction of therapy with Orencia in Period C.

Of the 26 children who received placebo during Period B who did not experience disease flares and then chose to receive open-label Orencia treatment during Period C, 76 per cent had an ACR Pedi 30 response, 68 per cent had an ACR Pedi 50 response, 60 percent had an ACR Pedi 70 Response and 36 percent had an ACR Pedi 90 response after re-introduction of therapy with Orencia in Period C.