- Biologics work on specific targets instead of the whole immune system.
- Biologics cause fewer side effects than older drugs for RA.
- Biologics may be used effectively as part of a combination treatment.
Biological response modifiers are the newest class of drugs used to treat rheumatoid arthritis (RA). These modern biologics have greatly improved treatment for many people with RA. Unlike older disease-modifying antirheumatic drugs (DMARDs), biologic DMARDs are made using biotechnology. They are genetically engineered to act like natural proteins in your immune system.
Your doctor may suggest that you start drug therapy right after your diagnosis. This can help combat joint damage. Methotrexate is often the first drug prescribed, but your doctor may give you a biologic drug if methotrexate doesn’t work well enough.
Biologics don’t cure RA, but they can dramatically slow its progression. Biologics also cause fewer side effects than older drugs. People who don’t respond to older RA drugs, such as methotrexate, may benefit from treatment with a biologic. Sometimes biologics may be given alone. Other times they may be given in combination with another type of drug. Taking a biologic drug with methotrexate is effective for most people with RA.
Biologic DMARDs available for rheumatoid arthritis include:
- tocilizumab (Actemra)
- certolizumab (Cimzia)
- etanercept (Enbrel)
- adalimumab (Humira)
- anakinra (Kineret)
- abatacept (Orencia)
- infliximab (Remicade)
- rituximab (Rituxan)
- golimumab (Simponi)
- tofacitinib (Xeljanz)
More new biologics are being tested and may be available soon.
Some of these drugs work fairly quickly. Others may take weeks or months to take full effect. Each person responds to these drugs differently, and not everyone responds well to the same drug. Some people may be able to take a biologic alone. However, many people will need a biologic plus an older drug.
Most biologics are given by injection. Some are injected under the skin. Others must be injected right into a vein. One drug, tofacitinib (Xeljanz), comes as a pill you take by mouth.
Biologics work by interrupting immune system signals involved in the damage of joint tissue. Many newer drugs target a protein called tumor-necrosis factor (TNF). These drugs are called anti-TNF biologics. Like other DMARDs, biologics affect immune system function.
Specific types of biologics
Biologics are sometimes better at controlling RA progression than DMARDs are. This is because they target specific mediators of RA inflammation. Older DMARDs work by suppressing the immune system in general. Modern biologic drugs for RA work in different ways in the body.
Abatacept works by crippling a type of white blood cell called T cells. T cells play a role in the inflammation that causes RA.
Many biologics work by interfering with the activity of tumor necrosis factor. This is a key immune system protein. These drugs include:
Rituximab appears to help control RA by destroying another category of immune system cells called B cells. The drug’s activity in the body is complex. These actions are not yet fully understood.
Anakinra blocks the action of an immune system protein called interleukin-1 (IL-1). IL-1 is often called a master cytokine. This is because it controls local and systemic inflammation in the body.
Tofacitinib is in a new class by itself. It’s called a Janus-associated kinase (JAK) inhibitor. It works by blocking a cellular signaling pathway inside cells. This stops components that cause inflammation from being made. Older biologics block inflammation from the outside of cells, but JAK-inhibitors work from within cells. Tofacitinib is the only biologic that isn’t injected. It comes as a pill, taken twice per day.
Biologics work for more people because they target specific parts of the immune system to reduce inflammation in the joints. They have fewer side effects than older drugs. Any drug that suppresses the immune system carries risks, though. Side effects can include:
- severe infections, such as lung infections
- liver damage
- reduced ability to make new blood cells
- pain or swelling at the injection site
Tell your doctor about any unusual symptoms you have. These include a fever or other symptoms that you can’t explain. For instance, biologics can cause a dormant infection to become active again. For this reason, you should have a tuberculosis test before taking one of these drugs.
People with liver disease may not be able to take a biologic drug. If you have liver issues, ask your doctor if biologics are safe for you.
Biologics are the newest type of drugs to treat RA. If you and your doctor are considering a biologic drug, keep the following in mind:
- Biologics may work better at controlling your symptoms than older RA medications do.
- Most biologics are given by injection. Only one drug, tofacitinib (Xeljanz), comes as an oral drug.
- Biologics tend to cause fewer side effects than older drugs. However, like all drugs, they may still cause side effects.
- There are several types of biologic drugs that each work to control your RA a little differently. Work with your doctor to choose the one that’s best for you.