BMS-819881 is a melaninconcentrating hormone receptor 1 (MCHR1) antagonist, which binds rat MCHR1 with a Ki of 7 nM and it also is selective and potent for CYP3A4 activity with an EC50 of 13 μM.

CYP3A4:13 μM （EC50）, MCHR1 (rat):7 nM （ki）

BMS-819881 (Compound 27) is 99.8% binds to rat serum proteins and rat MCHR1 Ki is 7 nM. When BMS-819881 is screened for cytochrome P450 (CYP) activity, EC50 values for CYP1A2, CYP2C9, CYP2C19, CYP2D6 are >40 μM; however, the CYP3A4 EC50 is 13 μM. The percent of BMS-819881 binds to serum proteins is species dependent ranging from 99.8%, 99.6%, and 99.3%, respectively, for rat, dog, and monkey. FLIPR-based assays establish that BMS-819881 is a potent and highly selective MCHR1 functional antagonist. BMS-819881 (Kb=32 nM) effectively blocks MCH stimulated Ca2+ mobilization in heterologous cells overexpressing MCHR1 but fails to inhibit MCH mediated Ca2+ mobilization of cells expressing MCHR2 at 10 μM. No activity is observed upon screening BMS-819881 at 10 μM versus a panel of 20 GPCRs associated with feeding homeostasis [1].

BMS-819881 has moderate terminal elimination half-life (t1/2=5.7 h, 32±8 h, and 14±3 h for rat (1 mg/kg, iv), dog (1 mg/kg, iv), and cynomologous monkey (1 mg/kg, iv))[1].