Biochem/physiol Actions

BI-2545 is a PF-8380 structure analog with improved autotaxin (ATX; ENPP2) inhibitory potency (human/rat ATX IC50 = 2.2/3.4 nM, IC50 = 29/96 nM using human/rat whole blood (WB); human ATX/rat ATX/rat WB IC50 = 6.5/13/307 nM with PF-8380), in vivo pharmacokinetic profile, oral availability, and lysophosphatidic acid (LPA)-lowering efficacy (BI-2545 Cmax/AUC/T1/2/Max 18:2 LPA reduction = 140 nM/675 nM•h/3.4 h/90.4% post 10 mg/kg p.o. in rats vs. 60.3 nM/342 nM•h/2.5 h/32.2% with PF-8380). BI-2545 exhibits no hERG inhibitory activity (IC50 >10 μM vs. 480 nM with PF-8380) and displays significant cross-reactivity towards only 4 targets among a panel of 48 enzymes/receptors/transporters/channel proteins at a high concentration of 10 μM (55%, 80%, 66%, 61% inhibtion of 5-HT2a, L-type Calcium channel, Na+ channel site 2, and norepinephrine transporter, respectively).