Baricitinib

Inhibitor of JAK1, JAK2

Structure

SERP Rating

In Cells

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In Model Organisms

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Probe Baricitinib is in the process of SERP review.

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Information

JAK1
JAK2

Inhibitor

up to 100 nM

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Probe Availability:

In Vitro Validations

Uniprot ID: P23458

Target Class: Kinase

Target SubClass: TK

Potency: IC 50

Potency Value: 5.9 nM

Potency Assay: Biochemical Assay (TR-FRET)

PDB ID for probe-target interaction (3D structure): --

Structure-activity relationship: yes

Target aliases:

Tyrosine-protein kinase JAK1, JAK1B, JAK1A, JAK1, ...

DOI Reference: 10.4049/jimmunol.0902819

In Cell Validations

In Vivo Data

Off-Target Selectivity Assesments

Potency end-point : IC50 Tyk2 53 nM, JAK3 560 nM, AAK1 17.2 nM, BIKE 39.8 nM, GAK134.4 nM, MPSK1 68.5 nM

Potency assay (off target): TR-FRET, ITC

Probe Selectivity in Vitro:

JAK3 IC50 ~ 560 nM, ~10-fold selectivity against Tyk2 (IC50 = 53 nM), c-Met (IC50 > 10,000 nM) and Chk2 (IC50 > 1,000 nM). Tested @ 500 nM against a diverse panel of 28 kinases with no significant inhibition observed. Additional Off Targets are (Kd): AAK1 17.2 nM, BIKE 39.8 nM, GAK134.4 nM , MPSK1 68.5 nM

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SERP ratings and comments

SERP Ratings

In Cell Rating

In Model Organisms

SERP Comments:

Baricitinib (alternatively named INCB28050, LY3009104) is an FDA-approved drug and a potent inhibitor of JAK1/2 with a decent in vivo profile. Baricitinib, however, is insufficiently profiled for use as a selective chemical probe. In vitro screening against a panel of 28 kinases identified off-target activities (IC₅₀: Tyk2 = 53 nM, JAK3 = 560 nM, AAK1 = 17.2 nM, BIKE = 39.8 nM, GAK = 134.4 nM, MPSK1 = 68.5 nM). Since there are 520 kinases in humans, it is likely that Baricitinib inhibits additional kinase off-targets. More selective JAK inhibitors are available—for instance, Filgotinib.

(last updated: 15 Apr 2025 )