abatacept (Orencia)

Introduction

Tradename: Orencia (FDA-approved 2005)

Indications

• FDA-approved for treatment of rheumatoid arthritis that does not respond adequately to methotrexate
• rheumatoid arthritis with inadequate response to etanercept (Enbrel) or infliximab (Remicade)
  • 50% response rate in clinical trial
• may be used concurrently with methotrexate or glucocorticoids

* preferred for patients with a history of severe infection

Contraindications

• concurrent use of other biologic agent (TNF inhibitor, rituximab, anakinra)
• relatively contraindicated with COPD

Pregnancy category: C

Dosage

• IV infusion every 28 days, with additional dose on day 14

Monitor

• screening for tuberculosis
• CBC, LFTs, serum creatinine baseline & every 3-6 months thereafter

• monitor with immunosuppressive agents

Adverse effects

• immunosuppression
• exacerbation of COPD
• similar to placebo

• drug adverse effects of immunosuppressive agents
• drug adverse effects of biologic immunosuppressive agents

Drug interactions

• do NOT use in combination with Enbrel, Humira or Remicade combination increases risk of infaction without increase in benefit

• drug interaction(s) of methotrexate with biological response modifier
• drug interaction(s) of biologic immunosuppressive agents

Mechanism of action

• soluble CTLA4 receptor/IgG Fc segment chimer
• inhibits T-cell activation
  • interferes with antigen presentation to T-cells
• targets CD80//CD86
• diminishes production of TNF & other immune modulators

Management

• whenever possible bring patients up to date on vaccinations prior to initiating biologic immunosuppressive agent

More general terms

• biologic immunosuppressive agent
• disease-modifying antirheumatic agent (DMARD)