Alk5 inhibitor | BI-4659

Target protein: 
Alk5
Probe Name: 
BI-4659
MOLECULAR WEIGHT [DA]: 
440.5
In stock: 
507

Chemical structure

Highlights

BI-4659 is a potent inhibitor of Alk5 (TGFßR1) with an IC50 value of 19 nM and shows selectivity against a broad panel of other kinases (see Selectivity section). BI-4659 blocks the phosphorylation of Smad2 and Smad3 in HaCaT cells with an EC50 of 185 nM. Together with the offered negative control BI-4101, BI-4659 is a suitable tool to test biological hypotheses in vitro.1 (BI-4659 = compound 47i, BI-4104 = compound 48 in reference 1).

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Target information

Transforming growth factor β (TGFβ) is a pluripotent cytokine involved in the regulation of various biological processes such as cell proliferation, differentiation, migration, adhesion, apoptosis, and epithelial-to-mesenchymal transition (EMT). Therapeutic approaches to inhibit its signaling by targeting TGFβ receptor I (TGFβRI/Alk5) are discussed for the treatment of diseases such as idiopathic pulmonary fibrosis (IPF) and cancer.2,3,4

BI-4659 inhibitor of Alk5 3D structure

Figure 3: Crystal structure of Alk5 complexed with a close analog of BI-4659 (PDB code 2X7O).1

In vitro Activity

Probe name / Negative control

BI-4659

BI-4101

MW [Da]

440.5

418.5

Inhibition of Alk5 (Kinase Glow assay, IC50) [nM]a

19

>50000

Inhibition of phosphorylation of Smad2 and Smad3 in HaCaT cells (EC50) [nM]

185

n.d.

a for detailed assay conditions see reference 1

In vitro DMPK and CMC parameters

Probe name / negative Control BI-4659 BI-4101

Solubility @ pH 6.8 [µg/ml

2 n.d.

Solubility @ pH 4 [µg/ml]

84 n.d.
Solubility @ pH 2 [µg/ml] 71 n.d.
CACO permeability @pH7.4 [*10-6 cm/s] 8 n.d.
CACO efflux ratio 6 n.d.
Microsomal stability (human/mouse/rat) [% QH] 26 23 <22 n.d.
Hepatocyte stability (human/mouse/rat) [% QH] n.d. n.d.
Plasma protein binding (human/mouse/rat) [%] n.d. n.d.
hERG [inh. % @ 10 µM] 38.5 n.d.
hERG IC50 [µM] >10 n.d.
CYP 3A4 (IC50) [µM] >50 n.d.
CYP 2C8 (IC50) [µM] >50 n.d.
CYP 2C9 (IC50) [µM] >50 n.d.
CYP 2C19 (IC50) [µM] >50 n.d.
CYP 2D6 (IC50) [µM] >50 n.d.

In vivo DMPK parameters

BI-4659 showed very high clearance in rat and therefore is not suited for in vivo studies

BI-4659 Rat

Clearance [%QH]

123

Mean residence [l/kg]a

1.7

tmax [h]b

3.3

Cmax [nM]b

27.7

F [%]b

50

Vss [l/kg]a

9

ai.v. 4.5 mg/kg

bp.o. 45 mg/kg

Negative control

MOLECULAR WEIGHT OF NEGATIVE CONTROL [DA]: 
418.5

BI-4101 shows no inhibition of Alk5 in the Kinase Glow assay (IC50 > 50 µM) and therefore is a suitable negative control for in vitro experiments.1 (BI-4101 = Compound 48 in reference 1.)

Alk5 negative control BI-4101 structure

Figure 4: BI-4101 which serves as a negative control

Selectivity

BI-4659 sows good selectivity in kinase panels. The compound shows no inhibition of 218/232 kinases tested at 2 µM. Cross-reactive kinases (%inhibition data at 0.2 µM): ABL1 (67), BLK (85), CSF1R (FMS) (82), FGR (91), FLT3 (66), FYN (74), LCK (100), LYN A (79), LYN (78), MAP4K5 (KHS1) (77), MELK (80), NTRK3 (TRKC) (78), RET (79), SNF1LK2 (96), YES1 (90).

BI-4659

Selectivity data available

Cerep®

No

Panlabs®

No

Invitrogen®

Yes

DiscoverX®

Yes

Dundee

Yes

Download selectivity data: 

Co-crystal structure of the BI probe compound and the target protein

No in-house structure is available for BI-4659, but for related compound (PDB code 2x7o).

reference molecules

SB-505124, SB-525334, GK6604, SD-208, LY-2157299, EW-7197, GW788388 and others. For a review on Alk5 kinase inhibitors in oncology see reference 5.

Summary

BI-4659 is a potent and selective inhibitor of Alk5 (IC50 = 19 nM) which effectively blocks cellular phosphorylation of Smad2/Smad3 in HaCaT cells (EC50 = 185 nM). We also offer BI-4101 as negative control. BI-4659 (5 mg) can be ordered free of charge together with BI-4101.1,6

Supplementary data