Last reviewed 2026-04-20 · How we verify

Xeljanz (tofacitinib)

Tofacitinib is a JAK inhibitor that prevents phosphorylation and activation of STATs.

Tofacitinib (Xeljanz) 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 absorption with peak concentrations within 0.5-1 hour for immediate-release formulation and 4 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. Tofacitinib represents an important oral alternative to biologic therapies for inflammatory arthropathies and inflammatory bowel disease in TNF-blocker-experienced patients.

At a glance

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

Boxed warnings

• WARNING: SERIOUS INFECTIONS, MORTALITY, MALIGNANCY, MAJOR ADVERSE CARDIOVASCULAR EVENTS, and THROMBOSIS WARNING: SERIOUS INFECTIONS, MORTALITY, MALIGNANCY, MAJOR ADVERSE CARDIOVASCULAR EVENTS, and THROMBOSIS See full prescribing information for complete boxed warning. • Increased risk of serious bacterial, fungal, viral, and opportunistic infections, including tuberculosis (TB), leading to hospitalization or death. Interrupt XELJANZ/XELJANZ XR treatment if serious infection occurs until the infection is controlled. Test for latent TB before and during therapy; treat latent TB prior to use. Monitor all patients for active TB during treatment, even patients with initial negative latent TB test. ( 5.1 ) • Higher rate of all-cause mortality, including sudden cardiovascular (CV) death with XELJANZ vs. TNF blockers in rheumatoid arthritis (RA) patients. ( 5.2 ) • Malignancies have occurred in patients treated with XELJANZ. Higher rate of lymphomas and lung cancers with XELJANZ vs. TNF blockers in RA patients. ( 5.3 ) • Higher rate of major adverse CV events (defined as CV death, myocardial infarction, and stroke) with XELJANZ vs. TNF blockers in RA patients. ( 5.4 ) • Thrombosis has occurred in patients treated with XELJANZ. Increased incidence of pulmonary embolism, venous and arterial thrombosis with XELJANZ vs. TNF blockers in RA patients. ( 5.5 ) SERIOUS INFECTIONS Patients treated with XELJANZ (tablets and oral solution) or XELJANZ XR (extended-release tablets) are at increased risk for developing serious bacterial, fungal, viral, and opportunistic infections, including tuberculosis (TB), that may lead to hospitalization or death [see Warnings and Precautions (5.1) and Adverse Reactions (6.1) ] . Most patients who developed these infections were taking concomitant immunosuppressants such as methotrexate or corticosteroids. Reported infections included: • Active TB, which may present with pulmonary or extrapulmonary disease. Patients should be tested for latent TB before XELJANZ/XELJANZ XR use and during therapy. Treatment for latent infection should be initiated prior to XELJANZ/XELJANZ XR use. • Invasive fungal infections, including cryptococcosis and pneumocystosis. Patients with invasive fungal infections may present with disseminated, rather than localized, disease. • Bacterial, viral, including herpes zoster, and other infections due to opportunistic pathogens. The risks and benefits of XELJANZ/XELJANZ XR treatment should be carefully considered prior to initiating therapy in patients with chronic or recurrent infection. Patients should be closely monitored for the development of signs and symptoms of infection during and after XELJANZ/XELJANZ XR treatment, including the possible development of TB in patients who tested negative for latent TB infection prior to initiating therapy. If a serious infection develops, interrupt XELJANZ/XELJANZ XR until the infection is controlled [see Warnings and Precautions (5.1) ] . MORTALITY In a large, randomized, postmarketing safety study in rheumatoid arthritis (RA) patients 50 years of age and older with at least one cardiovascular (CV) risk factor comparing XELJANZ tablets 5 mg or 10 mg twice a day to tumor necrosis factor (TNF) blockers, a higher rate of all-cause mortality, including sudden CV death, was observed with XELJANZ tablets 5 mg or 10 mg twice a day [see Warnings and Precautions (5.2) ] . XELJANZ 10 mg twice daily and XELJANZ XR 22 mg once daily dosages are not recommended for the treatment of RA, psoriatic arthritis (PsA), ankylosing spondylitis (AS), or polyarticular course juvenile idiopathic arthritis (pcJIA) [see Dosage and Administration (2.3, 2.4) ] . MALIGNANCIES Malignancies, including lymphomas and solid tumors, have occurred in patients treated with XELJANZ and other Janus kinase inhibitors used to treat inflammatory conditions. In RA patients, a higher rate of malignancies (excluding non-melanoma skin cancer (NMSC)) was observed in patients treated with XELJANZ tablets 5 mg or 10 mg twice a day compared with TNF blockers [see Warnings and Precautions (5.3) ] . Lymphomas and lung cancers were observed at a higher rate in patients treated with XELJANZ tablets 5 mg or 10 mg twice a day in RA patients compared to those treated with TNF blockers. Patients who are current or past smokers are at additional increased risk. MAJOR ADVERSE CARDIOVASCULAR EVENTS RA patients 50 years of age and older with at least one cardiovascular risk factor, treated with XELJANZ tablets 5 mg or 10 mg twice daily, had a higher rate of major adverse cardiovascular events (MACE) (defined as cardiovascular death, myocardial infarction, and stroke), compared to those treated with TNF blockers. Patients who are current or past smokers are at additional increased risk. Discontinue XELJANZ/XELJANZ XR in patients that have experienced a myocardial infarction or stroke [see Warnings and Precautions (5.4) ] . THROMBOSIS Thrombosis, including pulmonary embolism, deep venous thrombosis, and arterial thrombosis have occurred in patients treated with XELJANZ and other Janus kinase inhibitors used to treat inflammatory conditions. Many of these events were serious and some resulted in death. RA patients 50 years of age and older with at least one cardiovascular risk factor treated with XELJANZ tablets 5 mg or 10 mg twice daily compared to TNF blockers had an observed increase in incidence of these events. Avoid XELJANZ/XELJANZ XR in patients at risk. Discontinue XELJANZ/XELJANZ XR and promptly evaluate patients with symptoms of thrombosis [see Warnings and Precautions (5.5) ] .

Common side effects

• Upper respiratory tract infection
• Nasopharyngitis
• Colitis ulcerative
• Arthralgia
• Headache
• Urinary tract infection
• Influenza
• Blood creatine phosphokinase increased
• Abdominal pain
• Bronchitis
• Cough
• Juvenile idiopathic arthritis

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)

Key clinical trials

• A Study To Evaluate Both The Efficacy and Safety Profile of CP-690,550 In Patients With Moderately to Severely Active Ulcerative Colitis (PHASE3)
• A Phase 3 Study Comparing 2 Doses of CP-690,550 vs. Placebo for Treatment of Rheumatoid Arthritis (PHASE3)
• A 2-Year Phase 3 Study Of CP-690,550 In Patients With Active Rheumatoid Arthritis On Background Methotrexate (PHASE3)
• A Study Evaluating The Efficacy And Safety Of CP-690,550 In Patients With Moderate To Severe Ulcerative Colitis (PHASE3)
• A Phase 3 Study Comparing 2 Doses Of CP-690,550 And The Active Comparator, Humira (Adalimumab) Vs. Placebo For Treatment Of Rheumatoid Arthritis (PHASE3)
• Comparing The Effectiveness And Safety Of 2 Doses Of An Experimental Drug, CP-690,550, To Methotrexate (MTX) In Patients With Rheumatoid Arthritis Who Have Not Previously Received MTX (PHASE3)
• Long-Term Study Of CP-690,550 In Subjects With Ulcerative Colitis (PHASE3)
• A Study Comparing 2 Doses Of CP-690,550 Vs. Placebo For The Treatment Of Rheumatoid Arthritis In Patients On Other Background Arthritis Medications (PHASE3)

Patents

Primary sources

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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