Xeljanz and Xeljanz XR are prescription drugs used to treat rheumatoid arthritis, as well as other autoimmune conditions.

Rheumatoid arthritis, or RA, is an autoimmune condition. Patients with RA experience pain and tenderness in their joints because of their body’s autoimmune response. The condition can also affect the heart, skin, eyes, and lungs. RA generally flares up, rather than being a constant condition, and the pain can reportedly last for days or even weeks in patients. Unfortunately, there is no cure. Patients can only manage their pain and progression of the disease.

Xeljanz, generically known as tofacitinib, works by inhibiting enzymes that can exacerbate joint swelling and tenderness that occurs in patients with autoimmune disorders, such as RA.

According to the MedicineNet, the Xeljanz is part of a class known as Janus kinase (JAK) inhibitors. JAK is the enzyme responsible for chemical signaling that controls functions such as blood formation and immune responses. Xeljanz works by limiting the function of the JAK enzyme.

The drug was approved to treat RA by the Food and Drug Administration in 2012. Xeljanz is meant to be taken orally, usually at a 5 mg dose twice daily. Patients using Xeljanz or Xeljanz XR generally don’t respond to other treatments. However, the drug is forecasted to be lucrative for the manufacturer, Pfizer, who may make as much as $18 billion by 2023.

Xeljanz has since been approved to treat psoriatic arthritis, ulcerative colitis, and polyarticular course juvenile idiopathic arthritis as well.

Psoriatic arthritis can affect those who suffer from psoriasis. According to the Mayo Clinic, the main symptom of psoriasis is a red patchy rash with silver scales. However, the disease can also cause swelling in the joints.

Ulcerative colitis is a condition that affects the large intestine and colon. According to WebMD, ulcerative colitis ultimately results in ulcers after a period of swelling and inflammation.

Juvenile idiopathic arthritis (JIA) is a type of arthritis which affects children and teenagers. The cause of this disease is unknown, but is thought to be caused by pre-existing genetic factors activated by external factors such as viruses and bacteria. Polyarticular JIA is a specific type of the disease which affects more than five joints.

Listed side effects of Xeljanz include:

• Respiratory and urinary tract infections
• Sore throat
• Runny nose
• Headache
• Diarrhea
• Higher cholesterol levels
• Nasopharyngitis or swelling of the nasal passages

The FDA mandated a boxed warning for infections that can lead to serious injury or even death.

As a part of the FDA’s initial approval of Xeljanz, the drug maker, Pfizer, agreed to conduct a long-term clinical safety trial. The results of the most recent analysis of the data from the trial were released on Feb. 25, 2019, along with a Xeljanz blood clot warning from the agency.

According to the FDA Xeljanz warning, those taking a higher dose of the medication, 10 mg twice daily, face a higher risk of blood clots in the lungs, pulmonary embolism, deep vein thrombosis, or even death.

“During the most recent analysis of the trial, an external data safety monitoring committee found an increased occurrence of blood clots in the lungs and death in patients treated with tofacitinib 10 mg twice daily compared to patients treated with tofacitinib 5 mg twice daily or a TNF inhibitor,” states the FDA warning.

Xeljanz patients experiencing shortness of breath, chest pain, excessive sweating, or clammy skin should seek medical help immediately. Patients who are concerned about taking Xeljanz should not stop taking the drug until they have consulted with their physician.

In January 2021, Pfizer announced the co-primary endpoint results from the completed trial. Analysis of this data shows that Xeljanz patients may have additional risks beyond those previously identified. This includes an increased risk of heart problems and cancers.

According to Pfizer, the most common heart problem from the study was heart attacks and the most common cancer was lung cancer. However, other recorded cancers include lymphoma, breast cancer, melanoma, prostate cancer, and pancreatic cancer.

These results prompted an updated communication from the FDA regarding Xeljanz risks. The safety alert informs consumers and doctors of the risk for serious heart problems and cancers in Xeljanz patients. No further action has been taken by the agency, but, according to the alert, the FDA will continue to analyze the trial results and come to a final conclusion about Xeljanz safety.

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