How effective is tofacitinib citrate tablets in the treatment of psoriasis?

Tofacitinib is an oral drug that modulates immune responses by reversibly inhibiting the activity of Janus-associated kinases (JAKs) 1 and 3. JAK is a type of non-receptor tyrosine kinase that can phosphorylate a variety of proteins, thereby activating signal transducer and activator of transcription (STAT) proteins. The phosphorylated STAT protein dimerizes, enters the cell nucleus, and regulates the expression of related genes. The JAK-STAT pathway plays an important role in biological processes such as immune response, cell death, and tumor formation.

Tofacitinib was first approved by the U.S. Food and Drug Administration (FDA) in 2012 for the treatment of rheumatoid arthritis and other immune-mediated diseases. The study found that inhibiting JAK3 significantly reduced psoriasis-like inflammation in mouse models, a finding that prompted researchers to explore its potential in treating psoriasis in humans. Therefore, a series of randomized controlled trials (RCTs) were conducted to evaluate the efficacy of tofacitinib in patients with plaque psoriasis or psoriatic arthritis.

The results of the study showed that treatment with 5 mg of tofacitinib twice daily (BID) for 12 weeks significantly alleviated the main clinical manifestations of psoriasis compared with placebo. Specifically, the Psoriasis Area and Severity Index (PASI) score showed a hazard ratio of 4.38 for PASI 75 (≥75% reduction) and 21.68 for PASI 90 (≥90% reduction). Additionally, the physician's global assessment of the patient's skin condition (PGA 0/1) showed a hazard ratio of 3.93 for improvement.

There was no significant difference in PGA improvement between treatment with 5 mg of tofacitinib twice daily for 16 weeks compared with treatment with 5 mg of tofacitinib twice daily for 12 weeks (hazard ratio, 1.11). However, prolonging treatment time significantly increased the incidence of upper respiratory tract infection (URTI), with a hazard ratio of 1.89, suggesting that long-term use may have certain safety risks.

Reference materials:https://www.xeljanz.com/