Drug information of Abatacept

Abatacept

Drug group:

Abatacept is a soluble fusion protein, which links the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) to the modified Fc (hinge, CH2, and CH3 domains) portion of human immunoglobulin G1 (IgG1). Structurally, abatacept is a glycosylated fusion protein with a MALDI-MS molecular weight of 92,300 Da and it is a homodimer of two homologous polypeptide chains of 357 amino acids each. It is produced through recombinant DNA technology in mammalian CHO cells.

Mechanism of effect

Abatacept is a selective costimulation modulator, like CTLA-4, the drug has shown to inhibit T-cell (T lymphocyte) activation by binding to CD80 and CD86, thereby blocking interaction with CD28. Blockade of this interaction has been shown to inhibit the delivery of the second co-stimulatory signal required for optimal activation of T-cells. This results in the inhibition of autoimmune T-Cell activation that has been implcated in the pathogenesis of rheumatoid arthritis.

Pharmacodynamic

Abatacept Known as a recombinant fusion protein, the drug consists of the extracellular domain of human cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) linked to a modified Fc portion of human immunoglobulin G1 (IgG1(. CTLA4 is a naturally occurring protein which is expressed on the surface of T-cells some hours or days after full T-cell activation and is capable of binding to CD80/86 on antigen-presenting cells with much greater affinity than CD28. Binding of CTLA4-Ig to CD80/86 provides a negative feedback mechanism which results in T-cell deactivation.

Pharmacokinetics

Half-life, Terminal: 13 days

Peak Plasma: 295 mcg/mL

Vd: 0.07 L/kg

Clearance: 0.22 mL/hr/kg

Drug indications

artirit rhomatoid

Dosage

Adult

Rheumatoid Arthritis

IV infusion

  • <60 kg: 500 mg
  • 60-100 kg: 750 mg
  • >100 kg: 1000 mg
  • Maintenance: Above dose repeated q2Weeks X2, then q4Weeks

SC injection

  • SC administration may be initiated with or without an IV loading dose
  • IV Loading dose: Administer a single IV infusion (see IV infusion weight-based dosing)
  • Maintenance dose: 125 mg SC qWeek (first dose within a day following IV loading dose)
  • Patients unable to receive IV infusion may initiate weekly SC injections without loading dose
  • Transitioning from IV to SC: Administer first SC dose instead of scheduled IV dose

Psoriatic Arthritis

IV infusion

  • <60 kg: 500 mg
  • 60-100 kg: 750 mg
  • >100 kg: 1000 mg
  • Maintenance: Above dose repeated q2Weeks X2, then q4Weeks

SC injection

  • 125 mg SC qWeek without the need for an IV loading dose
  • Switching from IV to SC: Administer the first SC dose instead of the next scheduled IV dose

Pediatric

Juvenile Idiopathic Arthritis

SC administration

  • <2 years: Safety and efficacy not established
  • ≥2 years
    • 10 to <25 kg: 50 mg SC once weekly
    • 25 to <50 kg: 87.5 mg SC once weekly
    • ≥50 kg: 125 mg SC once weekly

IV administration

  • <6 years: Safety and efficacy not established
  • ≥6 years old and <75 kg: Loading dose of 10 mg/kg IV over 30 minutes 
  • Maintenance: Same dose repeated 2 and 4 weeks after loading dose, THEN q4Weeks
  • ≥75 kg: Administer as in adult

Alerts

Do not give live vaccines concurrently or less than 3 months after discontinuation

Higher risk for serious infections; discontinue if serious infections develop

Screen for latent TB before initiating; safety unknown in pts with latent TB

Patients should have all necessary immunizations before initiating therapy

Increased risk of lymphoma and lung cancer reported; significance unknown; increased risk of lymphoma associated with rheumatoid arthritis

Use caution in patients with COPD; exacerbations may occur

Higher incidence of infections and malignancy reported in the elderly; use caution

Points of recommendation

Do not shake the medication bottle or you may ruin the medicine. Prepare your dose only when you are ready to give an injection. Do not use if the medicine has changed colors or has particles in it.

Each single-use vial (bottle) or prefilled syringe of this medicine is for one use only. Throw away after one use, even if there is still some medicine left in it after injecting your dose.

If you need surgery, tell the surgeon ahead of time that you are using abatacept.

If you have ever had hepatitis B, abatacept can cause this condition to come back or get worse. You will need frequent blood tests to check your liver function during treatment and for several months after you stop using this medicine.

This medicine can cause false results with certain blood glucose tests, showing high blood sugar readings. If you have diabetes, talk to your doctor about the best way to check your blood sugar while you are using abatacept.

Autoimmune disorders are often treated with a combination of different drugs. Use all medications as directed by your doctor. Do not change your doses or medication schedule without your doctor's advice.

Store abatacept in the refrigerator. Do not freeze. Keep the medicine in original carton to protect it from light. Do not use abatacept if the expiration date on the medicine label has passed.

If you need to transport the medicine, place the syringes in a cooler with ice packs.

Abatacept that has been mixed with a diluent may be stored in a refrigerator or at room temperature and used within 24 hours.


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