Biologic agents are a new group of highly effective drugs for JIA. They target key steps in the immune system that cause inflammation in the joints.
How do biologics work?
In the immune system, chemicals called cytokines are released into the body, which affect the behavior and function of other cells. When you have an infection, certain cytokines can be released to control other cells to help fight the infection. In JIA, the immune system is releasing too many cytokines that control cells causing inflammation in your joints or tissues. Some of these cytokines are called tumour necrosis factor (TNF), interleukin-1, and interleukin-6. Biologic agents block some of these cytokines from being made. Biologics are used when other drugs have not effectively controlled the JIA.
By blocking cytokines, biologics can dramatically reduce inflammation. In some people, biologics can also prevent joint damage.
Biologics often work quickly. Improvements may often be noticed for some people within one to two weeks of starting the drug. Other people find it takes a month or so to see the benefits.
Things to know if you are taking a biologic agent
Before starting any biologic for JIA, you must be tested to make sure you have not been exposed to tuberculosis (TB). You may have been exposed to it at school or in your community and never even know it. To test for TB, you need to have a TB skin test and chest X-ray. A person who takes a biologic drug when they have TB can get very sick.
There may be other vaccines you could consider before starting treatment. One example is the chickenpox vaccine. The flu shot is recommended every year; it is given in the fall. After starting a biologic, you cannot take any live vaccines. Talk with your doctor about this.
All biologics make it harder to fight infections like colds, flu and skin infections. They can sometimes cause irritation at the injection site, flu-like symptoms and low blood counts (low white blood cells, red blood cells or platelets). For most people, however, the side effects are not a problem.
Finally, treatment with biologics is expensive. It can cost $15,000 to $25,000 or more a year. If your doctor recommends a biologic for you, your parents will need to look into what medication insurance they have for you. This may include private health insurance plans, provincial drug benefit programs, or other programs. A social worker can help your parents find ways to cover the cost of this treatment.
The following are the commonly prescribed biologics available and their possible side effects.
| Generic name | Most common brand name | How it is given | How the medication comes | Side effects |
|---|---|---|---|---|
| Etanercept | Enbrel | Injection under the skin, once a week | Injection | Most common side effects:
Rare side effects:
|
| Infliximab | Remicade | Intravenously every 1-2 months in a clinic or hospital | Infusion | Most common side effects:
Rare side effects:
|
| Adalibumab | Humira | Injection under the skin, every 2 weeks | Injection | Most common side effects:
Rare side effects:
|
| Anakinra | Kineret | Injection under the skin, once daily | Injection | Most common side effects:
Rare side effects:
|
| Canakinumab | Ilaris | Injection under the skin, once a month | Injection | Most common side effects:
Rare side effects:
|
| Abatacept | Orencia | Intravenously, usually once a month in hospital | Infusion | Most common side effects:
Rare side effects:
|
| Rituximab | Rituxan | Intravenously, high dose every 2 weeks for 2 doses or low dose once a week for 4 doses in hospital | Infusion | Most common side effects:
Rare side effects:
|
| Tocilizumab | Actemra | Intravenously, every 2-4 weeks in hospital | Infusion | Most common side effects:
Rare side effects:
|
Important safety points about taking biologics
- Deciding to start treatment with a biologic agent is a big decision. You should talk with your doctor about any special risks before you start, so that you understand what you need to watch for. If you have a history of tuberculosis (TB), recurrent infections, heart problems, multiple sclerosis or cancer, you should avoid starting a biologic agent. Please discuss the use of this medication with your doctor.
- You will need regular blood tests to check for any side effects from the biologic agent.
- Find out from your doctor or nurse who you should call if you get sick while taking a biologic. If you develop fever, chills or any signs of infection like a cough, sore throat, diarrhea or a new rash, DO NOT take the next dose of biologic. Call the health-care provider that your doctor or nurse has recommended you contact if you get sick, and make an appointment with your doctor. You need to be well again before you take the next dose. Speak with your doctor for further instructions.
- You should not receive live vaccines (MMR, varicella, nasal flu shot) while receiving biologics.
- You should be vaccinated against, or already have had, chicken pox before starting treatment with biologics.
- If you are exposed to or develop chickenpox, DO NOT take the next dose of biologic. Call your doctor for further instructions.
- Young people taking biologics should practice birth control. Because biologics are new drugs and have not been studied in pregnant women, we do not know if they are safe in pregnancy.
- Biologics have been used for a long time in adults with inflammatory arthritis. The use in children and teens is shorter since biologics were approved for use in children later than in adults. To date, biologics appear to be safe in both adults and children. However, the long-term safety in children and teens is unknown.
- There is a very small increase in risk of malignancy (cancer) in people who have taken biologics.
- A very small number of people on biologic drug therapy have developed other diseases of the immune system like lupus.
Another rare side effect of the TNF inhibitors is development of unusual neurologic symptoms. Like the risk of malignancy, it is not known how big this risk is, but your doctor will look for any signs of this side effect while you are on the medication.
Most side effects such as infection appear only while you are taking the biologics. It is not known whether the very rare side effects such as malignancy or neurologic problems improve or resolve when the biologics are stopped.
Upcoming medications
There are other biologic agents that are currently being developed and tested. Ask your health care team about these newer agents. They may be available in the near future.
