Key takeaways:
Janus kinase (JAK) inhibitors are medications that target specific enzymes (proteins) involved in inflammation. They’re made from chemicals and have simple structures. Biologics, on the other hand, are complex medications that come from living sources.
Because of how they’re made, JAK inhibitors aren’t the same as biologics. But like many biologics, they can have targeted effects in the body.
JAK inhibitors and biologics are used to treat several of the same medical conditions. And it’s possible that you may be prescribed one or the other — but not both.
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Xeljanz. Olumiant. Rinvoq. If you’re living with an autoimmune disorder, these medications may sound familiar. They all belong to a class of medications known as Janus kinase (JAK) inhibitors.
Biologics are also often used to treat autoimmune disorders. A few examples include Humira (adalimumab), Enbrel (etanercept), and Stelara (ustekinumab). But are JAK inhibitors like Xeljanz biologics, too? The short answer: No. Let’s review how they’re different below.
What are JAK inhibitors?
JAK inhibitors, also called jakinibs, are a specific group of medications that target a family of enzymes (proteins) called JAKs. JAK enzymes play an important role in a pathway linked to inflammation and autoimmune disorders. JAK inhibitors work by blocking one or more of these enzymes, lessening inflammation.
Most JAK inhibitors are available as oral pills, including:
Xeljanz (tofacitinib)
Jakafi (ruxolitinib)
Olumiant (baricitinib)
Cibinqo (abrocitinib)
Inrebic (fedratinib)
Rinvoq (upadacitinib)
Vonjo (pacritinib)
The one exception is Opzelura. It’s a topical cream version of ruxolitinib for eczema and vitiligo.
Are JAK inhibitors the same as biologics?
No. JAK inhibitors and biologics are different. It’s easy to confuse the two since both types of medications can have targeted effects in the body. But the main reason that JAK inhibitors aren’t considered biologics is because of how they’re made.
How are JAK inhibitors and biologics different?
JAK inhibitors are made from chemicals and have simple structures. Because of this, they’re considered small molecule drugs. Small molecule drugs have structures that are well-defined, making them easier to copy for generic versions.
Biologics, on the other hand, come from living sources, like animal or plant cells. Their structures are more complex, making them difficult to copy. Instead of generics, they have biosimilars — biologics that are highly similar to an original biologic.
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What’s more, biologics aren’t limited to medications that work one specific way. They include a diverse group of products that work in many different ways, from vaccines and insulins to gene therapy.
Are JAK inhibitors considered DMARDs?
Yes. JAK inhibitors are considered DMARDs, or disease-modifying antirheumatic drugs. But what exactly are DMARDs?
DMARDs are medications that help slow down an inflammatory health condition from getting worse. They typically fall into two categories: non-biologic and biologic DMARDs. JAK inhibitors are considered non-biologic DMARDs. And biologic DMARDs include injectables, like Humira and Enbrel.
Non-biologic DMARDs are often broken down further into conventional DMARDs and targeted synthetic DMARDs. Conventional DMARDs, like methotrexate, affect your body more broadly. Targeted synthetic DMARDs, like JAK inhibitors, only affect specific parts of your immune system.
What are JAK inhibitors and biologics used for?
There are several medical conditions that both JAK inhibitors and biologics are approved to treat. Examples include rheumatoid arthritis (RA), psoriatic arthritis, and inflammatory bowel disease. You’ll typically take one or the other for treatment — but not both.
Three JAK inhibitors — Jakafi, Inrebic, and Vonjo — are approved to treat a rare blood cancer called myelofibrosis. And Olumiant is one of the few medications approved to treat COVID-19.
Biologics have many different uses. Diabetes, cancer, and osteoporosis are a few examples. Genetic (inherited) conditions are also sometimes treated with biologics, like gene therapy. And vaccines are biologics used to prevent infection, as well as treat certain diseases.
When is a JAK inhibitor used instead of a biologic?
Typically, JAK inhibitors are reserved for when preferred treatments haven’t worked or aren’t an option for you. However, there are a few situations where your healthcare provider may consider one. Examples include:
You prefer oral medications over injections: For now, biologics are mostly available as injections. If you prefer taking pills instead, JAK inhibitors may be an option if other oral treatments haven’t worked well enough.
You’ve tried several biologics without success: Biologics don’t work for everyone. And for some people, they stop working after a while. If you’ve tried a few biologics without success, your healthcare provider may consider a JAK inhibitor.
You have heart failure: Certain biologics may potentially worsen or cause congestive heart failure. If you have pre-existing heart failure or develop heart failure during treatment, a different biologic or JAK inhibitor may be considered.
Your healthcare provider can discuss your options to help you find the best treatment for you.
When is a JAK inhibitor potentially not safe to use?
Certain JAK inhibitors have a boxed warning — the FDA’s most serious warning for a medication. This is due to an increased risk of major adverse cardiovascular events (like heart attack or stroke), cancer, and blood clots in certain at-risk people.
If you’re age 50 or older, your healthcare provider may avoid JAK inhibitors altogether if you have additional risk factors. Examples of these include:
Current smoking
Diabetes
High blood pressure
HDL (“good”) cholesterol less than 40
Family history of premature coronary heart disease
History of coronary artery disease
RA that has started affecting your organs (called extra-articular RA)
They may also avoid JAK inhibitors if you have a history of blood clots or cancer.
The bottom line
JAK inhibitors are chemical-based medications with simple structures. They work by targeting one or more JAK enzymes in the body. Because of how they’re made, JAK inhibitors are not the same as biologics.
JAK inhibitors and biologics are both used to treat several of the same medical conditions. But you’ll typically either be prescribed one or the other, not both. For most people, biologics are preferred over JAK inhibitors for autoimmune disorders. But your healthcare provider will determine which treatment is right for you.
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References
Arthritis Foundation. (n.d.). DMARDs.
Banerjee, S., et al. (2017). JAK-STAT signaling as a target for inflammatory and autoimmune diseases: Current and future prospects. Drugs.
Benjamin, O., et al. (2022). Disease modifying anti-rheumatic drugs (DMARD). StatPearls.
Favalli, E. G., et al. (2017). The management of first-line biologic therapy failures in rheumatoid arthritis: Current practice and future perspectives. Autoimmunity Reviews.
Fraenkel, L., et al. (2021). 2021 American College of Rheumatology guideline for the treatment of rheumatoid arthritis. Arthritis Care & Research.
Leukemia & Lymphoma Society. (n.d.). Myelofibrosis.
Lin, C. M. A., et al. (2020). Basic mechanisms of JAK inhibition. Mediterranean Journal of Rheumatology.
Tanaka, Y., et al. (2022). Janus kinase-targeting therapies in rheumatology: A mechanisms-based approach. Nature Reviews Rheumatology.
U.S. Food and Drug Administration. (2021). FDA requires warnings about increased risk of serious heart-related events, cancer, blood clots, and death for JAK inhibitors that treat certain chronic inflammatory conditions.
Ytterberg, S. R., et al. (2022). Cardiovascular and cancer risk with tofacitinib in rheumatoid arthritis. The New England Journal of Medicine.
