Obesity is one of the most common metabolic disorders in the world. According to the Centers for Disease Control and Prevention, nearly two-thirds of the adult population of the United States, the country with the highest prevalence of obesity worldwide, is overweight and more than half of these are frankly obese. The World Bank estimates that obesity alone accounts for more than 12% of the U.S. national health care budget. The National Institutes of Health estimated that direct costs for the treatment of obesity in 1998 had reached $102.2 billion dollars. As these statistics illustrate, obesity is a rapidly growing, costly disease, for which there is currently no effective treatment. Existing medications for the treatment of obesity have significant side effects that limit their use. A safe, effective, orally administered compound that not only produces - but also sustains - weight loss would be a breakthrough in the treatment of obesity, and would represent a significant advantage over currently available treatments.

Oleoyl estrone (OE), is an orally administered small molecule that has been shown to cause significant weight loss in extensive preclinical animal studies, without the need for dietary modifications. In such studies, OE appears to be safe and effective with no evidence of rebound weight gain after treatment has been discontinued. Developed by researchers at the University of Barcelona, OE has been tested in both obese and lean rats; treatment with OE resulted in significant weight loss even in the presence of abundant food and water. Manhattan Pharmaceuticals is the exclusive worldwide licensee of OE and its derivatives.

Manhattan Pharmaceuticals has discovered that the levels of oleoyl estrone (OE), which appears to play a key role in communicating levels of stored body fat to the brain, are significantly lower in obese patients than predicted on the basis of body weight. The company theorizes that raising OE levels in the obese will therefore suppress appetite and cause weight loss. Animal studies support this theory, with body weight reductions of 20%, and daily caloric intake reductions of 40% or more during OE treatment. At the 13^th European Congress on Obesity, held in Prague during May 2004, the company presented further preclinical study results substantiating the safety of OE in both male and female rats. Safety observations were made over a 14-day period, including mortality, gross toxicity, blood, urine and carcass chemistries, blood and urine cellular counts, organ weights and histology. In groups treated at therapeutic dose levels of oleoyl estrone, there were no histological effects on endocrine-responsive tissues such as testes, epididymis, prostate, seminal vesicle, vagina, uterus or mammary glands. None of the doses tested resulted in mortality.