JAK1 inhibitor
- JAK1 carries the γ-common-chain (IL-2, IL-4, IL-15), IL-6 and interferon signals → broad immunomodulation
- Selectivity over JAK2 is meant to spare erythropoietin and thrombopoietin signaling
- Class boxed warnings: serious infection, MACE, thrombosis, malignancy
- JAK1 carries the γ-common-chain (IL-2, IL-4, IL-15), IL-6 and interferon signals → broad immunomodulation
- Selectivity over JAK2 is meant to spare erythropoietin and thrombopoietin signaling
- Class boxed warnings: serious infection, MACE, thrombosis, malignancy
The JAK family at a glance
Four kinases, paired on cytokine receptors
- JAK1 + JAK3 — γ-common-chain cytokines (IL-2, -4, -7, -9, -15, -21)
- JAK2 + JAK2 — EPO, TPO, GH, GM-CSF
- JAK1 + TYK2 — type I interferons; JAK2 + TYK2 — IL-12, IL-23
Open the JAK inhibitors presentation →
Drugs with this mechanism (7)
- Abrocitinib — Oral JAK1 inhibitor for refractory atopic dermatitis; carries the JAK class boxed warning.
- Baricitinib — Oral JAK1/JAK2 inhibitor for rheumatoid arthritis, alopecia areata, and severe COVID-19.
- Momelotinib — JAK/ACVR1 inhibitor for myelofibrosis with anemia; improves spleen, symptoms, and transfusion burden.
- Peficitinib — Oral JAK inhibitor used for rheumatoid arthritis in some countries; serious infection and herpes-zoster risks.
- Ruxolitinib — JAK1/2 inhibitor for myelofibrosis and polycythemia vera; abrupt stop causes a cytokine flare.
- Tofacitinib — First oral JAK inhibitor; boxed warnings for thrombosis, malignancy and MACE.
- Upadacitinib — JAK1-selective inhibitor across rheumatology, dermatology and IBD.
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