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CP-690,550 (tofacitinib)

Pfizer · Phase 3 active Small molecule

Tofacitinib is a JAK inhibitor that blocks Janus kinase signaling to reduce inflammatory cytokine production and immune cell activation.

Tofacitinib is a JAK inhibitor that blocks Janus kinase signaling to reduce inflammatory cytokine production and immune cell activation. Used for Rheumatoid arthritis, Ulcerative colitis, Polyarticular course juvenile idiopathic arthritis.

At a glance

Generic nameCP-690,550 (tofacitinib)
Also known asMatching placebo to tofacitinib (same tablet or solution as the active arm).
SponsorPfizer
Drug classJAK inhibitor
TargetJAK1, JAK3, JAK2
ModalitySmall molecule
Therapeutic areaImmunology
PhasePhase 3

Mechanism of action

Tofacitinib selectively inhibits JAK1 and JAK3 (and to a lesser extent JAK2), which are intracellular kinases critical for signal transduction downstream of cytokine receptors including IL-2, IL-7, and IL-15. By blocking JAK-STAT signaling, the drug suppresses T-cell proliferation and reduces production of pro-inflammatory cytokines, thereby dampening the adaptive immune response in autoimmune and inflammatory conditions.

Approved indications

Common side effects

Key clinical trials

Primary sources

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SourceUsed for
ClinicalTrials.govTrial enrolment, design, endpoints, results

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