Rheumatoid arthritis is a type of inflammatory arthritis that causes the body's immune system to attack healthy tissues that line the joints. Biologics are designed to fight the immune cells that are attacking these healthy tissues.
Rheumatoid arthritis (RA) causes pain, swelling, and deformities in the joints. It can also cause flu-like symptoms, weight loss, and overall fatigue. For some people, its effects can be devastating and debilitating.
An estimated one-fifth of people with RA are work-disabled after 2 years of developing the disease. Several classes of medications are available to treat RA, including biologic treatments.
The United States Food & Drug Administration (FDA) approved the first biologic drug to treat RA in 1998. Since that time, the FDA has approved eight other similar drugs, as well as a newer synthetic drug.
At their most basic level, biologics are proteins that have been genetically modified to target the immune system cells that attack healthy cells and cause RA symptoms.
Biologics are a targeted form of therapy, which makes them different from some traditional RA treatments, such as methotrexate, which do not specifically attack certain cell types.
According to an article in the journal Clinical Pharmacology & Therapeutics, biologics can reduce the progression of damage to the joints caused by RA.
Biologic treatments are not always the first line of treatment for RA. Many people with RA have problems in multiple cell types that cause symptoms, but biologics can only target one type of cell.
While a doctor can prescribe multiple biologics, the number of side effects increases with additional medications.
Sometimes, a doctor will prescribe a biologic treatment in addition to other medications for RA. A person may find it takes time to discover the combination that works best for their unique symptoms.
Doctors categorize biologic treatments according to which cells they target. Categories of biologic treatments include:
Example drug(s): Rituximab (Rituxan)
How it works: B-cell inhibitors work by killing B-lymphocytes that can cause inflammation. This medication must be administered intravenously (IV) for two sessions every 6 to 12 months. Each session lasts 4 to 6 hours. A person who receives B-cell inhibitors via IV may be at risk for infection as well as transfusion reactions.
Example drug(s): Anakinra (Kineret)
How it works: Interleukin-1 blockers or IL-1 blockers target interleukin-1, an inflammatory compound in the body. These drugs are prescribed less often than other biologics for RA. IL-1 blockers must be self-injected once daily.
Example drug(s): Sarilumab (Kevzara); tocilizumab (Actemra)
How it works: These drugs keep interleukin-6 proteins from attaching to cells and causing inflammation. Sarilumab is an injection that a person must receive every 2 weeks. Tocilizumab is administered via IV once a month.
Example drug(s): Abatacept (Orencia)
How it works: These medications attach to the surface of T-cells, which are white blood cells that cause inflammation. Doctors administer the medicine by IV for 30 minutes every other week for 6 weeks. A person transitions to getting infusions every 4 weeks after that.
Tumor necrosis factor inhibitors (TNF-inhibitors)
How it works: These medications work by stopping tumor necrosis factor, which is responsible for the beginning stages of inflammation. These drugs are prescribed more frequently because they have the longest history as a treatment for RA. Infliximab is delivered via IV while the others can be given by self-injection.
Another biologic treatment type is tofacitinib (Xeljanz). This class of drugs targets the proteins that cause RA, known as the Janus kinases. However, this drug targets proteins inside the cell while all other biologic treatments target proteins outside the cells.
Unlike the other medications that must be taken via IV or injection, tofacitinib can be taken as a pill twice a day.
With the exception of tofacitinib (Xeljanz), most biologic treatments are taken either via IV infusion or by self-injection.
These medications cannot be made into a pill because the molecules contained within are usually considered too small to pass into the bloodstream.
As a result, they must be delivered directly into or very close to the blood. A doctor can discuss delivery methods as well as infusion or injection schedules.
Some biologic treatments work very quickly after they are administered. Others may need significantly more time to take effect.
The most common side effect of injectable or IV biologic treatments is infection. Administering biologics can irritate the skin's tissues and introduce unwanted bacteria and viruses that can lead to infections.
In addition, biologics affect immune system cells. As a result, a person's immune system may not be able to fight off infections as well.
Very rare side effects of biologic treatments include:
- demyelinating syndromes that damage nerve fibers, sometimes causing vision problems
- lupus-like syndrome development
- effects on liver enzymes
- reactivation of hepatitis B in people with a history of hepatitis B
- swelling of the hands and ankles, shortness of breath, or sudden onset of heart failure
A doctor should discuss potential risks with each treatment. Some biologics are associated with higher incidences of infection than others.
Biologic treatments have helped many people with RA experience a reduction in symptoms, as well as slow the progression of damage to affected joints.
Over the past decade, the amount of available biologic treatments has increased. Researchers are studying many potential medications that may help people with RA in the future. These medications are known as new biologics.
Another promising field is personalized medicine, where a doctor can use genetic biomarker tests to determine which biologics a person would best respond to. This can help make an individualized treatment plan.