What is Xeljanz (tofacitinib)?

From the Guidelines

Xeljanz (tofacitinib) is an oral Janus kinase inhibitor used to treat several autoimmune conditions, including rheumatoid arthritis, psoriatic arthritis, ulcerative colitis, and polyarticular juvenile idiopathic arthritis, by blocking specific enzymes involved in inflammation and immune responses.

Key Points

• Xeljanz works by blocking JAK1 and JAK3 enzymes, reducing inflammation and symptoms associated with these conditions 1.
• It is typically prescribed at doses of 5 mg or 10 mg twice daily, depending on the condition being treated 1.
• Patients should be aware of boxed warnings for serious infections, malignancy, major adverse cardiovascular events, and thrombosis (blood clots) 1.
• Before starting treatment, patients should undergo tuberculosis screening and have their immunization status updated, including consideration of the zoster vaccine (Shingrix) to reduce the risk of herpes zoster 1.
• Regular blood work monitoring is necessary during treatment to check for changes in blood cell counts, liver enzymes, and cholesterol levels 1.
• Xeljanz should not be taken with certain medications that affect the immune system, and patients should inform their healthcare provider about all medications they are taking to avoid potential interactions 1.

Important Considerations

• The recommended dose of tofacitinib for psoriasis is 5 mg by mouth 2 times a day or 10 mg by mouth 2 times a day, although it is not currently FDA approved for this indication 1.
• Tofacitinib 10 mg twice a day is associated with a higher risk of adverse effects, such as infection and cytopenia, compared with tofacitinib 5 mg twice a day 1.
• Tofacitinib should not be initiated if the lymphocyte count is <500 cells/mm3, absolute neutrophil count (ANC) is <1000 cells/mm3, or hemoglobin is <9 g/dL, and should be discontinued if these thresholds are reached during treatment 1.

From the Research

What is Xeljanz (Tofacitinib)?

• Xeljanz, also known as tofacitinib, is a potent, selective JAK inhibitor that preferentially inhibits Janus kinase (JAK) 1 and JAK3 2.
• It is used for the treatment of moderate to severe active rheumatoid arthritis (RA) in adult patients who have responded inadequately to, or who are intolerant of, one or more DMARDs 2, 3.
• Tofacitinib is also approved for the treatment of active psoriatic arthritis (PsA) in combination with methotrexate for patients who have had an inadequate response or who have been intolerant to a prior therapy with a disease-modifying antirheumatic drug (DMARD) 4.

Mechanism of Action

• Tofacitinib works by inhibiting the JAK family of tyrosine kinases, which are involved in the signaling of cytokines that play a role in inflammation and immune response 5.
• It mainly interacts with JAK1 and JAK3, which are involved in the development and function of T and B cells, and the production of inflammatory mediators 5.

Efficacy and Safety

• Clinical studies have shown that tofacitinib is effective in reducing signs and symptoms of disease and improving health-related quality of life (HR-QOL) in patients with RA and PsA 2, 3, 4.
• Tofacitinib has been shown to be generally well tolerated, with most adverse events being mild or moderate in severity 2, 3, 4.
• However, the incidence of herpes zoster (HZ) was higher with tofacitinib than in the general RA population, although infections were clinically manageable 2.