Abatacept (Orencia) is used to treat rheumatoid arthritis (RA), psoriatic arthritis (PsA), and polyarticular juvenile idiopathic arthritis (pJIA), which are autoimmune disorders, and is also used to prevent acute graft versus host disease (aGVHD). Abatacept works by preventing your body's immune system from attacking healthy tissues or graft tissues. The immune system helps your body fight infections. In people with autoimmune disorders, the immune system mistakes the body's own cells for invaders and attacks them.

Abatacept is a selective T-cell costimulation modulator.

T cells (T lymphocytes) are a type of white blood cell that is part of the immune system, activated T cells are involved in autoimmune disorders such as RA, pJIA, and PsA. Abatacept blocks T cells from becoming activated by binding to proteins on the cell surface called CD80 and CD86, which block interaction with a protein called CD28. This means the T cells are not fully activated, so helps relieve symptoms of  RA, pJIA, PsA, and acute graft versus host disease. 

Abatacept is not a cure for any autoimmune disorder and will only treat the symptoms of your condition.

Abatacept became an FDA-approved medicine on December 23, 2005.

Who can use abatacept?

Abatacept is FDA-approved to be used for:

• adult patients with moderately to severely active rheumatoid arthritis (RA)
• patients 2 years of age and older with moderately to severely active polyarticular juvenile idiopathic arthritis (pJIA).
• adult patients with active psoriatic arthritis (PsA)
• the prophylaxis of acute graft versus host disease (aGVHD), in combination with a calcineurin inhibitor and methotrexate, in adults and pediatric patients 2 years of age and older undergoing hematopoietic stem cell transplantation (HSCT) from a matched or 1 allele-mismatched unrelated donor.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Using abatacept with a TNF antagonist, other biologic RA/PsA therapy, or JAK Inhibitors can increase the risk of infections and serious infections. 

Hypersensitivity and anaphylaxis have occurred. 

Serious infections have been reported. 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 tuberculosis (TB) infection before starting abatacept therapy. Patients testing positive should be treated for TB  before starting abatacept treatment. 

You should be screened for viral hepatitis before starting abatacept.

Update vaccinations before starting treatment. Live vaccines should not be given concurrently or within 3 months of discontinuation. Abatacept may blunt the effectiveness of some immunizations. 

Chronic obstructive pulmonary disease (COPD) patients may develop more frequent respiratory adverse events. 

Cytomegalovirus (CMV) and Epstein-Barr Virus (EBV) reactivation in patients treated for aGVHD prophylaxis. 

Before you start treatment with abatacept, your doctor may perform tests to make sure you do not have tuberculosis or other infections.

For treatment of rheumatoid arthritis (RA), psoriatic arthritis (PsA), and polyarticular juvenile idiopathic arthritis (pJIA)

IV infusion: Abatacept may be given by a healthcare provider through a vein in your arm (intravenous infusion), this takes about 30 minutes to give you the full dose of medicine. You will then receive your next abatacept dose at 2 weeks and 4 weeks after the first dose, and then every 4 weeks.

Subcutaneous injection: Abatacept may also be given as an injection under your skin (subcutaneous). The abatacept is available as a prefilled syringe or ClickJect autoinjector for home use. Your healthcare provider will prescribe the type that is best for you. If your healthcare provider decides that you or a caregiver can give your injections of abatacept prefilled syringes or abatacept ClickJect autoinjectors at home, you or your caregiver should receive training on preparing and injecting this medicine. Do not try to inject this medicine until you have been shown the right way to give the injections by your healthcare provider.

Your healthcare provider will tell you how much abatacept to use and when to use it.

For preventative treatment of aGVHD:

You will receive abatacept by a healthcare provider through a vein in your arm (intravenous infusion) over 60 minutes on the day before transplantation (Day -1). You will then receive abatacept on Days 5, 14, and 28 after transplantation.
Your healthcare provider may give you antiviral medicines before, during, and after transplant to help prevent Epstein-Barr Virus (EBV) and Cytomegalovirus (CMV) infections.

General administration information

Read and carefully follow any Instructions for Use provided with your medicine. Ask your doctor or pharmacist if you don't understand all the instructions.

Prepare an injection only when you are ready to give it. Gently swirl but do not shake the medication bottle. Do not use it if the medicine looks cloudy, has changed colors, or has particles in it. Call your pharmacist for new medicine.

Each vial (bottle) or prefilled syringe is for one use only. Throw it away after one use, even if there is still medicine left inside.

Use a needle and syringe only once, then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

If you need surgery, tell the surgeon beforehand you are using abatacept.

If you've ever had hepatitis B, using abatacept can cause this virus to become active or worsen. You may need frequent liver function tests while using this medicine and for several months after you stop.

Abatacept 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 you should test your blood sugar.

Autoimmune disorders are often treated with a combination of different drugs. Use all medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice.

Usual Adult Dose for Rheumatoid Arthritis:

IV Dosing Regimen:
Weight less than 60 kg: 500 mg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter.
Weight 60 to 100 kg: 750 mg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter.
Weight more than 100 kg: 1000 mg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter.
Subcutaneous Dosing Regimen:
Optional IV loading dose:

• Weight less than 60 kg: 500 mg IV once.
• Weight 60 to 100 kg: 750 mg IV once.
• Weight more than 100 kg: 1000 mg IV once

Subcutaneous injection: 125 mg subcutaneously once a week
Comments:
This drug may be used as monotherapy or concomitantly with disease-modifying antirheumatic drugs (DMARDs) other than Janus kinase (JAK) inhibitors or biologic disease-modifying antirheumatic drugs (bDMARDS), such as tumor necrosis factor (TNF) antagonists.
The IV infusion should be administered over 30 minutes.
Before the first subcutaneous dose, an optional loading dose may be administered as a single IV infusion; if an IV loading dose is used, the first subcutaneous injection should be administered within 1 day of the infusion.
For patients switching from IV therapy to subcutaneous administration, the first subcutaneous dose should be administered instead of the next scheduled IV dose.
Use: For the treatment of patients with moderately to severely active rheumatoid arthritis

Usual Adult Dose for Psoriatic Arthritis:

IV Dosing Regimen:
Weight less than 60 kg: 500 mg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter
Weight 60 to 100 kg: 750 mg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter
Weight more than 100 kg: 1000 mg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter
Subcutaneous Dosing Regimen: 125 mg subcutaneously once a week
Comments:
This drug may be used with or without nonbiologic DMARDs.
The IV infusion should be administered over 30 minutes.
For patients switching from IV therapy to subcutaneous administration, the first subcutaneous dose should be administered instead of the next scheduled IV dose.
Use: For the treatment of patients with active psoriatic arthritis

Usual Adult Dose for Graft Versus Host Disease - Prophylaxis:

10 mg/kg IV on the day before transplantation (Day -1), then 10 mg/kg IV on Days 5, 14, and 28 after transplantation
Maximum dose: 1000 mg/dose
Comments:
Before administering this drug, recommended antiviral prophylaxis for Epstein-Barr virus (EBV) reactivation should be administered and continued for 6 months after hematopoietic stem cell transplantation (HSCT); additionally, prophylactic antivirals for CMV infection/reactivation should be considered during therapy and for 6 months after HSCT.
The IV infusion should be administered over 60 minutes.
Use: In combination with a calcineurin inhibitor and methotrexate, for the prophylaxis of acute graft versus host disease (aGVHD) in patients undergoing HSCT from a matched or 1 allele-mismatched unrelated-donor

Usual Pediatric Dose for Juvenile Idiopathic Arthritis:

IV Dosing Regimen:
6 years or older:
Weight less than 75 kg: 10 mg/kg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter
Weight 75 to 100 kg: 750 mg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter
Weight more than 100 kg: 1000 mg IV initially, at 2 and 4 weeks, and every 4 weeks thereafter
Maximum dose: 1000 mg/dose
Subcutaneous Dosing Regimen:
2 years or older:
Weight 10 to less than 25 kg: 50 mg subcutaneously once a week
Weight 25 to less than 50 kg: 87.5 mg subcutaneously once a week
Weight at least 50 kg: 125 mg subcutaneously once a week
Comments:
This drug may be used as monotherapy or concomitantly with methotrexate.
The IV infusion should be administered over 30 minutes.
Subcutaneous administration: Patients may self-inject or the patient's caregiver may administer this drug if both the health care provider and parent/legal guardian decides it is appropriate; the ability of pediatric patients to self-inject with the autoinjector has not been tested.
Use: For the treatment of patients with moderately to severely active polyarticular juvenile idiopathic arthritis

Usual Pediatric Dose for Graft Versus Host Disease - Prophylaxis:

2 to less than 6 years: 15 mg/kg IV on the day before transplantation (Day -1), then 12 mg/kg IV on Days 5, 14, and 28 after transplantation
6 years or older: 10 mg/kg IV on the day before transplantation (Day -1), then 10 mg/kg IV on Days 5, 14, and 28 after transplantation
Maximum dose: 1000 mg/dose
Comments:
Before administering this drug, recommended antiviral prophylaxis for EBV reactivation should be administered and continued for 6 months after HSCT; additionally, prophylactic antivirals for CMV infection/reactivation should be considered during therapy and for 6 months after HSCT.
The IV infusion should be administered over 60 minutes.
Use: In combination with a calcineurin inhibitor and methotrexate, for the prophylaxis of aGVHD in patients undergoing HSCT from a matched or 1 allele-mismatched unrelated-donor.

You should not use abatacept if you are allergic to it or any of the in

Before using abatacept, tell your doctor if you have ever had tuberculosis if anyone in your household has tuberculosis, or if you have recently traveled to an area where tuberculosis is common.

Tell your doctor if you have ever had:

• a weak immune system;
• any type of infection, including a skin infection or open sores;
• infections that go away and come back;
• COPD (chronic obstructive pulmonary disease);
• diabetes;
• hepatitis; or
• if you are scheduled to receive any vaccines.

Using abatacept may increase your risk of developing certain types of cancer such as lymphoma (cancer of the lymph nodes). This risk may be greater in older adults. Talk to your doctor about your specific risk.

Children using abatacept should be current on all childhood immunizations before starting treatment.

Pregnancy

Tell your healthcare provider if you are pregnant, become pregnant, or plan to become pregnant, as it is not known if abatacept can harm your unborn baby.  If you take abatacept during pregnancy, your name may be listed on a pregnancy registry to track the effects of abatacept on the baby.

Breastfeeding

Tell your doctor if you are pregnant or breastfeeding. It is not known if abatacept passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you use abatacept

Call your doctor for instructions if you miss your abatacept dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Do not receive a "live" vaccine while using abatacept, and for at least 3 months after your treatment ends. The vaccine may not work as well during this time, and may not fully protect you from disease. Live vaccines include measles, mumps, rubella (MMR), rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

Avoid being near people who are sick or have infections. Tell your doctor at once if you develop signs of infection.

Common abatacept side effects

• fever
• nausea, diarrhea, stomach pain
• headache
• cold symptoms such as stuffy nose, sneezing, sore throat, or cough.

Serious abatacept side effects

Get emergency medical help if you have signs of an allergic reaction hives, difficulty breathing, swelling of your face, lips, tongue, or throat.

Some side effects may occur during the injection. Tell your caregiver right away if you feel dizzy, light-headed, itchy, or have a severe headache or trouble breathing within 1 hour after receiving the injection.

You may get infections more easily, even serious or fatal infections. Call your doctor right away if you have signs of infection such as

• fever, chills, night sweats, flu symptoms, weight loss
• feeling very tired
• dry cough, sore throat, or
• warmth, pain, or redness of your skin.

Call your doctor at once if you have any of these other serious side effects:

• trouble breathing;
• stabbing chest pain, wheezing, cough with yellow or green mucus;
• pain or burning when you urinate; or
• signs of skin infection such as itching, swelling, warmth, redness, or oozing.

This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your other medicines, especially:

• adalimumab;
• anakinra;
• certolizumab;
• etanercept;
• golimumab;
• infliximab;
• rituximab; or
• tocilizumab.

This list is not complete. Other drugs may affect abatacept, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.