Ligand Pharmaceuticals Incorporated is developing LGD-6972, a novel, orally-bioavailable addition to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. The mechanism of action of LGD-6972 is to reduce the excess liver glucose production characteristic of type 2 diabetes mellitus that is a major contributor to hyperglycemia. This clinical trial will evaluate the safety and tolerability of escalating doses LGD-6972 administered daily over 2 weeks in both healthy subjects and subjects with type 2 diabetes mellitus.