More than half of the Unites States population is significantly overweight or obese. Currently, more than 20% of the U.S. population is considered to be clinically obese and the trend is toward even larger percentages. Despite the magnitude of the affected population, few therapeutic options are available.

There are many co-morbidities associated with obesity — of particular concern are hypertension, dyslipidemia and cardiovascular disease — each of which can significantly reduce life-expectancy. The costs to society of addressing these diseases are substantial and represent an increasing burden on the healthcare system.

Long viewed primarily as a behavioral disorder — to be treated with calorically restricted diets and increased exercise — the discovery of leptin in 1995 helped to shift treatment approaches toward an understanding of physiological causes and pharmaceutical interventions. Safe and effective long-term treatment of human obesity remains a critical unmet human health need.