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Xeljanz (Tofacitinib Citrate)
Tofacitinib inhibits Janus kinase enzymes to prevent STAT phosphorylation and activation.
Tofacitinib is a JAK inhibitor indicated for moderately to severely active rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and ulcerative colitis in patients with inadequate response or intolerance to TNF blockers. The drug demonstrates rapid oral absorption with a 3-hour half-life for immediate-release formulation and 6-8 hours for extended-release, with hepatic metabolism via CYP3A4 as the primary clearance mechanism. Significant drug interactions exist with CYP3A4 inhibitors and inducers requiring dosage modifications or contraindication, and concomitant use with biologic DMARDs or potent immunosuppressants is not recommended. The mechanism of action through JAK inhibition provides an alternative pathway for immune modulation in inflammatory conditions.
At a glance
| Generic name | Tofacitinib Citrate |
|---|---|
| Sponsor | Pfizer |
| Drug class | JAK inhibitor |
| Target | Janus kinase (JAK) enzymes |
| Modality | Small molecule |
| Therapeutic area | Immunology |
| Phase | FDA-approved |
| First approval | 2012 |
Mechanism of action
Tofacitinib is a Janus kinase (JAK) inhibitor that modulates intracellular signaling pathways. JAKs are intracellular enzymes which transmit signals arising from cytokine or growth factor-receptor interactions on the cellular membrane to influence cellular processes of hematopoiesis and immune cell function. Tofacitinib modulates the signaling pathway at the point of JAKs, preventing the phosphorylation and activation of Signal Transducers and Activators of Transcription (STATs) which modulate intracellular activity including gene expression. JAK enzymes transmit cytokine signaling through pairing of JAKs (e.g., JAK1/JAK3, JAK1/JAK2, JAK1/TyK2, JAK2/JAK2). Tofacitinib inhibited the in vitro activities of JAK1/JAK2, JAK1/JAK3, and JAK2/JAK2 combinations with IC50 of 406, 56, and 1377 nM, respectively. However, the relevance of specific JAK combinations to therapeutic effectiveness is not known.
Approved indications
- Juvenile idiopathic arthritis, extended oligoarthritis
- Juvenile psoriatic arthritis
- Polyarticular juvenile idiopathic arthritis
- Psoriatic arthritis
- Rheumatoid arthritis
- Ulcerative colitis
Common side effects
- Herpes zoster
- Upper respiratory tract infection
- Bronchitis
- Nasopharyngitis
- Urinary tract infection
- Rheumatoid arthritis
- Hepatic function abnormal
- Hypertension
- Fall
- Upper respiratory tract inflammation
- Back pain
- Arthralgia
Drug interactions
- Strong CYP3A4 Inhibitors (e.g., ketoconazole)
- Moderate CYP3A4 Inhibitors Concomitantly Used with Strong CYP2C19 Inhibitors (e.g., fluconazole)
- Strong CYP3A4 Inducers (e.g., rifampin)
- Immunosuppressive Drugs (e.g., azathioprine, tacrolimus, cyclosporine)
Patents
| Patent | Expiry | Type |
|---|---|---|
Primary sources
Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.
| Source | Used for |
|---|---|
| FDA label | Mechanism, indications, dosing, boxed warnings, drug interactions |
| FDA Orange Book | Patents + exclusivity |
Competitive intelligence
For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:
- Xeljanz CI brief — competitive landscape report
- Xeljanz updates RSS · CI watch RSS
- Pfizer portfolio CI