Alk5 inhibitor | BI-4659
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).
Share buttons
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
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
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.)
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 |
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
