Could a JAK Inhibitor Be Right for Your Rheumatoid Arthritis?

Last updated: March 2021

Disease-modifying anti-rheumatic drugs (DMARDs) have changed the landscape of rheumatoid arthritis (RA) treatment and improved the quality of life for many people living with the condition. However, only about 30 percent actually reach remission. Many more continue to have painful symptoms.1,2

Hoping to help close that gap is a relatively new class of DMARDs called Janus kinase (JAK) inhibitors. As options for treating RA continue to grow, several factors can help you and your doctor decide if a JAK inhibitor is the right treatment for your RA.1-4

What is a JAK inhibitor?

RA is a chronic condition that happens when the immune system does not work properly. Instead of protecting the body from disease, it attacks healthy tissues and causes an overactive inflammatory response. A DMARD is often prescribed to treat the symptoms of RA.1-4

JAK inhibitors are target-specific DMARDs that affect enzymes, called jakinibs, which are believed to play a role in inflammation. The inflammation results in joint pain, swelling, and stiffness. Over time, the disease can progress and damage the joints permanently. JAK inhibitors reduce inflammation and may prevent long-term joint damage that can happen when RA is not controlled.1-4

How is this different from other RA treatments?

JAK inhibitors are unique because they target only jakinib enzymes (JAK1, JAK2, and JAK3). The jakinibs send chemical messages that can trigger inflammation. Some other treatments work outside the cell, but the JAK inhibitors work inside the cell to help block that signal.1,3

Many traditional treatments for RA may take weeks or several months to work. One difference with JAK inhibitors is they can start working much faster to relieve symptoms, sometimes within days.2,4

Also, many other drugs for RA are given by injections or infusions. JAK inhibitors are taken orally which may be preferable to some people.1,3

Who should take a JAK inhibitor?

A JAK inhibitor can be used for moderate to severe RA when the first drug for treating RA doesn’t work well enough, or if the first therapy causes unpleasant side effects.

One study looked at people who did not respond well with other therapies. Significantly more patients had at least 20 percent improvement in their RA compared to placebo after taking a JAK inhibitor for 3 months. 1,2

Combined use of methotrexate and a JAK inhibitor

Or, they can be added to another treatment, like methotrexate. Methotrexate is usually one of the first drugs used to treat RA. Combining the 2 can help some people get better results. A study showed that significantly more people who added a JAK inhibitor saw an improvement over 6 months versus placebo.1-3

Medications that are available

There are 3 JAK inhibitors approved by the FDA for treating RA:1,3

Xeljanz (tofacitinib) was approved in 2012 to be used if methotrexate did not work well or could not be tolerated.1,3

Olumiant (baricitinib) was approved in 2018 to be used for people who have tried at least one other medicine called a tumor necrosis factor (TNF) antagonist that did not work well enough or could not be tolerated.1,3

Rinvoq (upadacitinib) was approved in 2019 to be used if methotrexate did not work well or could not be tolerated.5

Things to consider

JAK inhibitors work by suppressing the immune system. This can make it harder for the body to fight infections. It can also increase the risk of getting cancers like lymphoma or skin cancer. People who take JAK inhibitors may need to be tested for tuberculosis (TB), a serious infection that affects the lungs.1-4

Other possible serious side effects are blood clots, pneumonia, or herpes zoster. Since JAK inhibitors have not been around as long as other treatments, there is limited long-term safety data.1,2,4

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