Abatacept, a selective costimulation modulator, inhibits T cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. This interaction provides a costimulatory signal necessary for full activation of T lymphocytes. Activated T lymphocytes are implicated in the pathogenesis of RA and PsA and are found in the synovium of patients with RA and PsA.

In vitro, abatacept decreases T cell proliferation and inhibits the production of the cytokines TNF alpha (TNFα), interferon-γ, and interleukin-2. In a rat collagen-induced arthritis model, abatacept suppresses inflammation, decreases anti-collagen antibody production, and reduces antigen specific production of interferon-γ. The relationship of these biological response markers to the mechanisms by which ORENCIA exerts its clinical effects is unknown.

ORENCIA is a selective T cell costimulation modulator indicated for:

Adult Rheumatoid Arthritis (RA)

• Moderately to severely active RA in adults. ORENCIA may be used as monotherapy or concomitantly with DMARDs other than TNF antagonists.
  Juvenile Idiopathic Arthritis
• Moderately to severely active polyarticular juvenile idiopathic arthritis in patients 2 years of age and older. ORENCIA may be used as monotherapy or concomitantly with methotrexate.

Adult Psoriatic Arthritis (PsA)

• Active PsA in adults.

Important Limitations of Use

• Should not be given concomitantly with TNF antagonists. 

Subcutaneous Administration for Adult RA

• Administer by subcutaneous injection once weekly with or without an intravenous loading dose. For patients initiating therapy with an intravenous loading dose, administer a single intravenous infusion (as per body weight categories above), followed by the first 125 mg subcutaneous injection given within a day of the intravenous infusion.
• Patients transitioning from ORENCIA intravenous therapy to subcutaneous administration should administer the first subcutaneous dose instead of the next scheduled intravenous dose. 

Intravenous Administration for Juvenile Idiopathic Arthritis

• Pediatric patients weighing less than 75 kg receive 10 mg/kg intravenously based on the patient’s body weight. Pediatric patients weighing 75 kg or more should be administered ORENCIA following the adult intravenous dosing regimen, not to exceed a maximum dose of 1000 mg. Intravenous dosing has not been studied in patients younger than 6 years of age.

See package insert for complete information.

Most common adverse events (≥10%) are headache, upper respiratory tract infection, nasopharyngitis, and nausea.

None.

• Concomitant use with a TNF antagonist can increase the risk of infections and serious infections.
• Hypersensitivity, anaphylaxis, and anaphylactoid reactions.
• Patients with a history of recurrent infections or underlying conditions predisposing to infections may experience more infections.
• Discontinue if a serious infection develops.
• Screen for latent TB infection prior to initiating therapy. Patients testing positive should be treated prior to initiating ORENCIA.
• Live vaccines should not be given concurrently or within 3 months of discontinuation.
• Patients with juvenile idiopathic arthritis should be brought up to date with all immunizations prior to ORENCIA therapy.
• Based on its mechanism of action, ORENCIA may blunt the effectiveness of some immunizations.
• COPD patients may develop more frequent respiratory adverse events.