How Orencia Differs From TNF Blockers

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Orencia (abatacept) was approved by the U.S. Food and Drug Administration (FDA) on Dec 23, 2005 as the latest drug to treat the signs and symptoms of rheumatoid arthritis. Orencia joined three other biological DMARDs at the time of slowing the progression of structural damage, including the tumor necrosis factor antagonists (anti-TNF drugs):

    Simponi (golimumab) and Cimzia (certolizumab pegol), two more TNF blockers, were approved later.

    Orencia is approved for moderately to severely active rheumatoid arthritis patients who have had an inadequate response to one of the disease-modifying drugs (DMARDs) which in addition to the TNF antagonists include:

    How Orencia Is Administered

    Similar to Remicade (infliximab), Orencia is given as an intravenous infusion (IV). Orencia though is administered over 30 minutes, unlike infliximab which is administered over about 2 hours.

    Following the initial administration, Orencia is given at 2 and 4 weeks, then every 4 weeks thereafter. Orencia may be used as monotherapy (alone) or concomitantly with other DMARDs that are not TNF antagonists due to an increased risk of toxicity with the combination.

    As of July 2011, a subcutaneous self-injectable formulation of Orencia was approved by the FDA.

    Side Effects Associated With Orencia

    Side effects include but are not limited to:

    • allergic reactions that rarely can be life-threatening
    • infection
    • respiratory problems (especially in patients with underlying chronic obstructive pulmonary disease and malignancies)

    Facts to Consider Before Trying Orencia

    The cost of Orencia including its monitoring is most likely more than the injectable TNF antagonists adalimumab and etanercept but less than infliximab.

    Orencia has shown only mild benefit when used alone so it is best prescribed with another DMARD such as methotrexate or others to achieve optimal results.

    Until there is more clinical experience with Orencia, some doctors reserve it for patients who have failed at least two out of the three TNF antagonists (measured by unpleasant side effects or lack of benefit). These arthritis drugs have been on the market since etanercept was introduced in 1999 and demonstrate a favorable benefit-risk ratio.

    Orencia vs. Anakinra

    Anakinra is seldom used to treat rheumatoid arthritis due to its need for daily injections and the limited benefit compared to the TNF antagonists which block the activity of TNF (a cytokine or messenger between cells). TNF is a compound that has a key role in causing the inflammation and damage in rheumatoid arthritis.

    T cells also play a role in causing the clinical signs and symptoms of rheumatoid arthritis. Orencia blocks the signal in the blood that is necessary for T cells to do their damage. Kineret (anakinra) blocks the cytokine IL-1 which plays a role in the damage to the bone that is part of rheumatoid arthritis.

    Answer provided by Scott J. Zashin, M.D., clinical assistant professor at University of Texas Southwestern Medical School, Division of Rheumatology, in Dallas, Texas. Dr. Zashin is also an attending physician at Presbyterian Hospitals of Dallas and Plano. He is a fellow of the American College of Physicians and the American College of Rheumatology and a member of the American Medical Association.

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