Manhattan Pharmaceuticals, Inc has expanded the clinical trial sites for its ongoing phase 2a study of oral oleoyl-estrone (OE) in obese adult subjects to the US. OE is the company's orally administered product candidate in development for the treatment of obesity.

In addition to recruiting patients in Switzerland, where the phase 2a was initiated in May 2006, the study will now also begin recruiting patients at Jean Brown Research in Salt Lake City, UT and at Pennington Biomedical Research Center in Baton Rouge, LA. Screening of patients has already begun and dosing is expected to take place in mid November 2006.

This ongoing phase 2a study is a randomized, double blind, placebo-controlled, parallel group study. Approximately 100 obese adult subjects with a body mass index (BMI) of 27-38.9 will be randomized into one of four treatment groups to evaluate safety, preliminary efficacy, and pharmacokinetics of two 14-day dosing cycles of 5mg, 10mg, or 20mg of oral OE compared to placebo given once daily during each 14-day dosing cycle. In addition to safety and tolerability, this phase 2a study is also designed to further evaluate weight loss, maintenance of weight loss, and other therapeutic outcomes.

Manhattan also recently announced the initiation of a second phase 2a clinical trial of OE in morbidly obese male subjects (BMI 40-55) being conducted at St. Luke's-Roosevelt Hospital Center.

OE is an orally administered, synthetic form of oleoyl-estrone, a molecule that exists naturally in the body. As shown in animal studies, it is believed to work by a dual mechanism of action. Centrally, OE appears to act at the hypothalamus, resetting the body's ponderostat, the "food control center" in the brain that detects and integrates signals that control both appetite and metabolic behaviour. Peripherally, OE also causes reduced storage of fat in "white fat" tissue and allows skeletal muscle to use fat as an alternate energy source.