Biological response modifiers are a new 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 (bDMARDs) are made using biotechnology. They’re genetically engineered to act like natural proteins in your immune system.

Your doctor may suggest that you start drug therapy right after your diagnosis, which can help address joint damage.

While biologics don’t cure RA, they can slow its progression. They can also cause fewer side effects than other kinds of drugs.

Your doctor may give you a biologic drug alongside or in place of the drug methotrexate, an anti-rheumatic. Taking a biologic drug with methotrexate is effective in treating RA for many people.

Some biologics block the action of an immune system protein called interleukin-1 (IL-1). IL-1 is often called a master cytokine because it controls local and systemic inflammation in the body.

Biologic DMARDs (bDMARDs) work by targeting immune system pathways.

They often inhibit various proteins, receptors, and cells that cause inflammation such as interleukin-6 (IL-6), interleukin-1 (IL-1), c-reactive protein (CRP), and CD80/86.

bDMARDs in this class of drugs the Food and Drug Administration (FDA) approved for rheumatoid arthritis include:

  • tocilizumab (Actemra): an interleukin 6 (IL-6) inhibitor
  • sarilumab (Kevzara): an IL-6 inhibitor
  • anakinra (Kineret): an IL-1β inhibitor
  • abatacept (Orencia): an CD80/86 inhibitor
  • rituximab (Rituxan): an antibody against the protein CD20

Tumor necrosis factor alpha, or TNF alpha, naturally occurs in the body. It can increase in people with RA, causing pain and swelling.

TNF-alpha inhibitors help to inhibit this increase in TNF. Biologic DMARDs also include TNF-alpha inhibitors such as:

Biosimilars are categorized as TNF-alpha inhibitors or bDMARDs and are similar enough to current biologics to produce similar results.

Biosimilars used to treat RA include:

  • adalimumab-afzb (Abrilada)
  • adalimumab-atto (Amjevita)
  • infliximab-axxq (Avsola)
  • adalimumab-adbm (Cyltezo)
  • etanercept-szzs (Erelzi)
  • etanercept-ykro (Eticovo)
  • adalimumab-bwwd (Hadlima)
  • adalimumab-fkjp (Hulio)
  • adalimumab-adaz (Hyrimoz)
  • infliximab-dyyb (Inflectra)
  • infliximab-abda (Renflexis)

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, but many people will need a biologic plus another class of drug.

Most biologics are given by injection. Some are injected under the skin. Others must be injected directly into a vein.

Biologics work by interrupting immune system signals involved in the inflammatory process that result in damage to joint tissue.

The first type of biologic approved for use in treating RA was designed to target the protein called TNF. These drugs are called anti-TNF biologics, and they block specific steps in the inflammatory process.

While they don’t suppress the immune system broadly like conventional DMARDs, they do affect immune system function.


Biologics are sometimes better at controlling RA progression than other DMARDs because they target specific mediators of RA inflammation. These newer biologic drugs work in different ways in the body.

Some of these drugs disrupt certain chemical signals that participate in the inflammation, or they can work directly on T-cells or B-cells to interfere with the inflammatory process.

Many biologics work by interfering with the activity of tumor necrosis factor (TNF), a key immune system protein.

Tofacitinib (Xeljanz) is in a new class of drugs called Janus-associated kinase (JAK) inhibitors.

It’s classified as an oral non-biologic DMARD. 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 isn’t injected. It comes as a pill that’s taken twice per day.

Upadacitinib (Rinvoq) and Olumiant (baricitinib) are other new JAK inhibitors that’s taken orally. Upadacitinib received FDA approval to treat RA in 2019. Olumiant received FDA approval to treat TA in 2018.

Biologics work in treating RA for more people because they target specific parts of the immune system to reduce inflammation in the joints.

This means they can have fewer side effects than other types of drugs. But any drug that suppresses the immune system carries risks.

Side effects can include:

  • severe infections, such as lung infections
  • liver damage
  • reduced ability to make new blood cells
  • nausea
  • pain or swelling at the injection site
  • potentially increased risk of certain types of cancers

Some medications used to treat RA that affect the immune system do have the potential to increase cancer risk, particularly lymphomas.

In people living with autoimmune arthritis, the severity of the inflammation has been associated with increased risk for lymphoma in the past.

More recent research has suggested that these medications may not increase cancer risk, so more research is needed. For many living with other risks, the benefits of managing RA outweigh any higher risks of cancer.

Tell your doctor about any unusual symptoms you have, which can 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 and hepatitis screening 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 relatively new. If you and your doctor are considering a biologic drug, keep the following in mind:

  • Biologics may work better at managing your symptoms than older RA medications.
  • Most biologics are given by injection.
  • 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 work to manage your RA a little differently. Work with your doctor to choose the best option for you.