What class of drug is tofacitinib (Janus kinase inhibitor)?

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Last updated: April 9, 2025View editorial policy

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From the Guidelines

Tofacitinib is a Janus kinase inhibitor, which is a class of drug that interrupts the Janus kinase/signal transduction pathway. This class of medication is used to treat various inflammatory conditions, including rheumatoid arthritis, psoriatic arthritis, and ulcerative colitis, as approved by the FDA 1. The mechanism of action of tofacitinib involves blocking the activity of JAK enzymes, which are involved in signaling pathways that trigger inflammation in the body. Some key points about tofacitinib include:

  • It has shown beneficial effects in psoriasis, although it is not currently approved for this indication 1
  • It is available in oral formulations, including immediate-release and extended-release tablets, as well as an oral solution
  • The dosing regimen varies depending on the condition being treated, with rheumatoid arthritis typically requiring 5 mg twice daily or 11 mg once daily
  • JAK inhibitors, including tofacitinib, carry boxed warnings for serious infections, malignancy, major adverse cardiovascular events, and thrombosis, so regular monitoring is essential during treatment 1. Tofacitinib's efficacy and safety have been demonstrated in multiple large phase III clinical trials, including the Oral treatment Psoriasis Trial (OPT) Pivotal 1 and OPT Pivotal 2, which investigated its use in psoriasis 1.

From the FDA Drug Label

Tofacitinib is a Janus kinase (JAK) inhibitor. The class of drug that tofacitinib belongs to is a Janus kinase (JAK) inhibitor 2.

  • Key points:
    • Tofacitinib modulates the signaling pathway at the point of JAKs, preventing the phosphorylation and activation of STATs.
    • It inhibited the in vitro activities of JAK1/JAK2, JAK1/JAK3, and JAK2/JAK2 combinations.

From the Research

Classification of Tofacitinib

  • Tofacitinib is classified as a Janus kinase (JAK) inhibitor 3, 4, 5.
  • It is a disease-modifying antirheumatic drug (DMARD) that preferentially inhibits Janus kinase (JAK) 1 and JAK3 3.
  • Tofacitinib is the first approved drug in a new class of DMARDs, the JAK inhibitors 4.

Mechanism of Action

  • Tofacitinib works by selectively inhibiting JAKs, which have a pivotal role in triggering cytokine-induced signal transduction pathways that influence normal and pathological cellular processes of haematopoiesis and immune cell function 4.
  • The inhibition of JAKs by tofacitinib potentially modulates inflammatory processes and provides a novel approach for the treatment of rheumatoid arthritis (RA) 4.

Therapeutic Use

  • Tofacitinib is indicated 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 3.
  • It is also used to treat psoriatic arthritis (PsA) and ankylosing spondylitis (AS) 6.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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