The first JAK inhibitor, Xeljanz (Tofacitinib), was approved for use by the FDA for rheumatoid arthritis use in 2012. It was a breakthrough medication for RA as it was the first to offer a targeted drug in pill form. It also added to the arsenal of drugs that would possibly ease the symptoms of RA.

At this time there are three  JAK inhibitors  for RA. They are taken once a day in extended-release form. The three drugs are similar in action. However, it is recommended that if one doesn’t work,  you can still try another.

The synthetic, small molecule JAK inhibitors work by  suppressing   the Janus kinase enzymes that are involved in the process of inflammation.  These drugs are classified as DMARDs, Disease Modifying  Anti-Rheumatic Drugs. A JAK inhibitor  may be prescribed when a TNF inhibitor no longer works.

• A TB test is ordered as the JAK inhibitor may reactivate a dormant TB.
• Lipids, liver enzymes, CBC and other labs are ordered before these drugs are prescribed and periodically during treatment as the JAK inhibitors affect the lipids, liver enzymes and blood count.
• The shingles vaccine is given. If the chicken pox virus is dormant in an individual, , the JAK inhibitor may cause shingles.

Common side effects include diarrhea, cold symptoms, shingles, headache. May increase cholesterol numbers.

As convenient as these drugs are to take, do not take the black box warnings lightly. The complications from JAK inhibitors do happen to real people.

For a while the JAK inhibitors, pills, like Pfizer’s tofacitinib, Xeljanz, seemed like they would be a good alternative .  Tofacitinib was approved in 2012. At the time there was concern about its increased rate of infections and malignancies.

A multinational safety Oral Surveillance study was initiated in 2014 because of the above concerns. The final study analysis was published in the New England Journal of Medicine. Tofacitinib’s increased risk of major adverse cardiovascular events and incident cancers was documented. A black box warning is now included on all JAK inhibitors for risk of major cardiac event and for malignancies. The JAK inhibitors were no longer attractive.

Black box warnings are similar to those for the biologics.

• serious infections(fungal infections, TB)
•  lymphoma
•  malignancies   
• blood clotting disorders
•  heart disorders
• Tears in the GI tract

Pregnancy and Breastfeeding

Not recommended for use during pregnancy or breastfeeding. The JAK inhibitors are not safe for the fetus. In animal studies Rinvoq did  pass through milk. For women of childbearing age,  birth control is recommended while taking JAK inhibitors.

There are three JAK inhibitors currently approved for treatment of rheumatoid arthritis in the United States.

• Xeljanz (Tofacitinib)                                                                                          The first JAK inhibitor approved for RA. It was first developedas an immunosuppressant for organ transplants by NIH(National Institutes of Health)and Pfizer working together.  The original prescription was for 5mg twice a day. The new version Xeljanz ER 11mg is taken once a day.  List price $2500.00/month.
• Olumiant (Baricitinib)                                                                                A second JAK inhibitor that was approved in 2018 for Eli Lily. The prescription is 2mg once a day. List price $2300/month.
• Rinvoq (Upadacitinib), developed by AbbVie, is a third JAK inhibitor that was approved in 2019.  The prescription is 15mg extended-release tablets. It has been widely advertised on television.  List price$5100.00/mo.

These prices are for those without insurance. With insurance the patient cost is much less. My insurance company classifies the biologics and the JAK inhibitors as class five which is a $300/month copay. My copay at the VA for the same is $25/month.