MGL-3196 is an agonist of thyroid hormone receptor β (TRβ; EC
50s = 0.21 and 3.74 μM for TRβ and TRα, respectively).
1 It also inhibits ether-a-go-go-related gene (ERG) potassium channels (IC
50 = 30 μM). MGL-3196 is a liver-directed compound, with a liver to plasma ratio of 8:1 in mice with diet-induced obesity (DIO), which reduces the likelihood of adverse effects from systemic exposure. It does not affect the expression of α-myosin heavy chain (α-MHC) in a rat model of hypothyroidism, an effect mediated by TRα, indicating low potential for cardiac adverse effects. MGL-3196 lowers non-HDL cholesterol and liver triglycerides without affecting thyroid stimulating hormone (Tsh) levels in rat and rabbit models of hypercholesterolemia. It also lowers plasma glucose levels and improves insulin sensitivity in DIO mice. Formulations containing MGL-3196 are in clinical trials for the treatment of non-alcoholic steatohepatitis (NASH) and familial hypercholesterolemia.
