Orencia is a powder that is made up into a solution for infusion (drip into a vein). It contains the active substance abatacept.
|Table of Contents|
|What is it used for?|
|How is it used?|
|How does it work?|
|How has it been studied?|
|What benefits has it shown during the studies?|
|What is the risk associated?|
|Why has it been approved?|
Orencia is used in combination with methotrexate (a medicine that acts on the immune system) to treat the following diseases:
moderate to severe active rheumatoid arthritis an immune system disease causing damage and inflammation in the joints in adults aged 18 years or over who have not had an adequate response to other medicines including methotrexate or a tumour necrosis factor TNF blocker
moderate to severe active polyarticular juvenile idiopathic arthritis a rare childhood disease causing inflammation of many joints in patients from six years of age who have not had a sufficient response to other medicines including one TNF blocker.
The medicine can only be obtained with a prescription.
Treatment with Orencia should be started and supervised by a specialised doctor who has experience in the diagnosis and treatment of rheumatoid arthritis.
Orencia is given as an infusion lasting 30 minutes. The dose to use depends on the patient?s weight. It is given every two weeks for the first three doses, and then every four weeks. If there is no response within six months, the doctor should consider whether treatment should continue or not.
The active substance in Orencia, abatacept, is a protein that has been designed to suppress the activity of ?T cells?, immune system cells that are involved in causing the inflammation in rheumatoid and polyarticular juvenile idiopathic arthritis. T cells must be ?activated? before they work. This happens when some signal molecules attach to receptors on the surface of the T cells. Abatacept has been designed to attach to two of these signal molecules called CD80 and CD86. This stops them activating the T cells, helping to reduce the inflammation and other symptoms of the diseases.
Abatacept is produced by a method known as ?recombinant DNA technology?: it is made by a cell that has received a gene (DNA), which makes it able to produce abatacept.
In rheumatoid arthritis, Orencia has been studied in three main studies involving a total of 1,382 adults. The first two studies included a total of 991 patients who had not had an adequate response to methotrexate in the past, and the third included 391 patients who had not had an adequate response to TNF blockers in the past. All three studies compared the effects of adding Orencia or placebo (a dummy treatment) to the other medicines that the patients were already taking for rheumatoid arthritis: these did not include a TNF blocker. The main measures of effectiveness were the reduction in symptoms of arthritis after six months of treatment, as well as physical function (the ability to carry out everyday tasks) and the amount of damage to the joints (assessed using X-rays).
In polyarticular juvenile idiopathic arthritis, Orencia has been studied in one main study involving patients aged between six and 17 years whose previous treatment had failed. All of the patients received Orencia for four months, before the 122 who responded were then either switched to placebo or continued receiving Orencia. The main measure of effectiveness was how long it was before the patient?s disease flared up again. Around three-quarters of the patients were also taking methotrexate.
In rheumatoid arthritis, Orencia was more effective than placebo in improving symptoms in all of the studies. In the first study, 61% of the patients adding the approved dose of Orencia to methotrexate had a reduction in symptoms (70 out of 115), compared with 35% of the patients adding placebo (42 out of 119). The second study showed a similar effect of Orencia on symptoms of rheumatoid arthritis, as well as improved physical function and a reduced rate of joint damage after a year of treatment.
In the study of patients with an inadequate response to TNF blockers in the past, adding Orencia to existing treatment led to 50% of the patients having a reduction in symptoms (129 out of 256), compared with 20% of the patients adding placebo (26 out of 133). Patients taking Orencia also had a greater improvement in physical function after six months.
In polyarticular juvenile idiopathic arthritis, it took longer for the disease to flare up in the patients continuing to receive Orencia than those who switched to placebo. Over six months, 20% of the patients receiving Orencia had a flare-up (12 out of 60), compared with 53% of those receiving placebo (33 out of 62).
The most common side effect in adults taking Orencia (seen in more than 1 patient in 10) is headache. In younger patients, side effects are similar to adults, but nausea (feeling sick) is also seen in more than 1 patient in 10. For the full list of all side effects reported with Orencia, see the package leaflet.
Orencia should not be used in patients who may be hypersensitive (allergic) to abatacept or any of the other ingredients. It must not be used in patients with severe and uncontrolled infections, such as sepsis (when bacteria and their toxins circulate in the blood and start to damage the organs) or ?opportunistic? infections (infections seen in patients with a weakened immune system). Patients who receive Orencia are given a special alert card that explains this restriction and instructs them to contact their doctor immediately if they develop an infection during a course of treatment.
The CHMP concluded that Orencia had a modest anti-inflammatory effect in rheumatoid arthritis, and in combination with methotrexate, led to a reduction in the worsening of joint damage and an improvement in physical function. It also concluded that Orencia could be a valuable new tool in the treatment of polyarticular juvenile idiopathic arthritis. The Committee decided that Orencia?s benefits are greater than its risks and recommended that it be given marketing authorisation.