T here are many different treatment options for psoriatic arthritis, and since everyone is unique, some will work better for you than others.
The newest class of drugs approved by the Food and Drug Administration (FDA) to treat psoriatic arthritis are Janus kinase inhibitors, or JAK inhibitors. If you want to know more about how JAK inhibitors work and if they might be a good treatment for your needs, we’re here to help you learn more.
“We're beginning to learn more and more about psoriatic arthritis and about what treatments work for it,” says Arthur Mandelin, MD, PhD, associate professor of medicine and rheumatology at Northwestern Feinberg School of Medicine in Chicago.
And JAK inhibitors provide the most targeted approach to treating psoriatic arthritis yet.
7 Essential Facts About JAK Inhibitors for Psoriatic Arthritis
1. JAK inhibitors are the newest, most targeted psoriatic arthritis treatment.
Traditional disease-modifying treatment options include DMARDs, which suppress the immune system on a broad level, and biologics, which are more targeted in how they block immune system activity. But JAK inhibitors work in an even more targeted way. They block specific pathways in the immune response that are thought to be involved in psoriatic arthritis. By blocking the inflammation at its source, the overactive immune response does not “turn on.” This results in better control of disease activity.
2. There are currently two FDA-approved JAK inhibitors for psoriatic arthritis.
In 2017, the FDA approved tofacitinib (Xeljanz) to treat psoriatic arthritis. In late 2021, they also approved upadacitinib (Rinvoq). A third drug, called baricitinib (Olumiant) — approved to treat rheumatoid arthritis (RA) — is currently under investigation for use with psoriatic arthritis.
3. JAK inhibitors are taken orally, on a daily basis.
JAK inhibitors are often compared to biologics, as they are both targeted types of psoriatic arthritis treatment. Biologics are given as self-injections, which need to be refrigerated, or by infusion in a medical setting. Biologics need to be administered in intervals ranging from weekly to monthly. By contrast, JAK inhibitors are available in pill form, which you simply take by mouth. “They're definitely less cumbersome in that way,” Mandelin says. “The flip side of it is that they also wash in and wash out of the body quickly. That’s why they are taken daily.”
4. JAK inhibitors start working within three months (or sooner).
How quickly JAK inhibitors take effect can vary from person to person. But if they are going to help you, you’ll notice results within three months, Mandelin says. “There are some data out there that suggest some people can experience a meaningful difference as early as two weeks on a JAK inhibitor,” he notes.
A telltale sign that they’re working? You’ll notice you have fewer symptoms. Your doctor will be able to quantify this through blood testing and by asking you questions during your regular checkups.
5. JAK inhibitors are effective, but they may not work for everyone.
A study published in March 2020 in the journal Current Dermatology Reports found that tofacitinib is very effective in treating psoriatic arthritis. But that doesn’t mean it’s guaranteed to work for everyone. “If a JAK inhibitor is not helpful, patients often go back to biologics,” Mandelin says.
You can also try the other approved JAK inhibitor to see if that works for you — unless you experienced a side effect specific to the drug class as a whole — adds Nilanjana Bose, MD, a rheumatologist at Memorial Hermann in Houston.
6. JAK inhibitors are safe but do come with some risks.
A study published in April 2020 in the Chinese Medical Journal found that an increased risk of infections, such as upper respiratory, was among the most common side effects of JAK inhibitors in people with psoriatic arthritis. This is because JAK inhibitors target parts of the immune system, which can lower your overall immunity.
The safety of JAK inhibitors has also made recent headlines. Results from a postmarketing study of tofacitinib delayed FDA approval of certain JAK inhibitors used for RA as treatment for psoriatic arthritis. Findings showed an increased risk of serious heart-related problems and cancer in people taking tofacitinib for RA. As a result, a black box warning was added — to all JAK inhibitors, not just tofacitinib.
This is why your doctor may not prescribe a JAK inhibitor if you have cardiovascular issues or a history of blood clots. “But rather than being scared by a warning, I think people with psoriatic arthritis should view this as a caution, as with any kind of [treatment], and do their due diligence,” Dr. Bose adds.
This includes checking your heart health profile, among other things. “Before starting, we also test people to make sure they don’t have any dormant infections in their system that could be woken back up by starting a JAK inhibitor,” according to Mandelin. You may be tested for things such as tuberculosis, hepatitis B, or hepatitis C before you start treatment. Your doctor will also monitor you during the course of treatment for signs of infection. Other possible side effects may include an allergic reaction to the medication or negative effects to the liver, but these are rare, he says.
7. JAK inhibitors can be expensive, but financial assistance is available.
Even with insurance coverage, JAK inhibitors can still come with significant out-of-pocket costs. “They are very expensive for most people,” says Mandelin. “It does depend on your insurance, but they do tend to be a little bit cheaper than biologics.”
Although JAK inhibitors are costly, they are still cheaper than spending money on a treatment that doesn’t work. A study published in August 2020 in the Journal of Managed Care & Specialty Pharmacy found that for those who did not find success with a traditional disease-modifying antirheumatic drug (DMARD) or a biologic, tofacitinib was associated with a reduction in psoriatic arthritis symptoms and a lower total cost of treatment.
Your doctor may also be able to point you to patient assistance programs, charitable foundations, or other financial options to help lower the cost of JAK inhibitor treatment.
Is It Time to Try a JAK Inhibitor?
JAK inhibitors are typically prescribed to people who have moderate to severe psoriatic arthritis only when other disease-modifying treatments haven’t worked. “Right now, JAK inhibitors cannot be used as a first-line treatment,” says Bose.
The types of psoriatic arthritis treatment options include:
- Nonsteroidal anti-inflammatory drugs (NSAIDs) to help alleviate joint pain and swelling
- DMARDs — such as methotrexate, a common first-line treatment — to slow disease progression
- Biologics, such as tumor necrosis factor (TNF) inhibitors or interleukin (IL)-17 inhibitors, to target and block specific inflammatory response pathways in the body
- JAK inhibitors, which are the most targeted disease-modifying therapy
- Immunosuppressants to lessen an overactive immune response
- Steroids to reduce inflammation and ease symptoms, especially during a flare
- Enzyme inhibitors to slow down the inflammatory response
Because advanced psoriatic arthritis is more likely to cause joint damage, it’s important to get the condition under control. In many cases, if you haven’t responded to other disease-modifying psoriatic arthritis drugs, a JAK inhibitor may be worth a try.
Common Questions About JAK Inhibitors for Psoriatic Arthritis
Next Steps: Making Psoriatic Arthritis Treatment Decisions
You’ve learned a lot about JAK inhibitors for psoriatic arthritis. So what’s next?
Take some time to absorb all of this info and decide if JAK inhibitors are something you might want to consider.
Before your next appointment, think about your current treatment plan and how well it’s controlling your psoriatic arthritis.
- Are you satisfied with your current treatment?
- Has it improved your psoriatic arthritis symptoms as well as you had hoped?
- Are you downplaying your symptoms to your doctor?
- How frequently do you cancel plans or activities because of psoriatic arthritis?
- Are you able to follow your treatment regimen as prescribed?
- Have you tried other treatments to see if they help you manage your psoriatic arthritis?
If you’re having trouble finding a psoriatic arthritis treatment plan that works for you, you might want to talk to your doctor about JAK inhibitors. Here are a few conversation starters that you can ask at your next appointment.
- Do you think it’s possible for me to gain better control of my psoriatic arthritis?
- What else can I do to better manage my psoriatic arthritis?
- Am I a good candidate for a JAK inhibitor?
- If so, what type of results should I expect?
- How often should I monitor the progress of my treatment?