Manhattan Pharmaceuticals, Inc. has received Swiss regulatory approval to commence its Phase IIa study with oral Oleoyl-estrone (OE), the company's drug candidate for the treatment of obesity.

The single centre, Phase IIa study is a randomized, double-blind, placebo-controlled, parallel group study designed to evaluate the safety, preliminary efficacy, and pharmacokinetics of two 14-day dosing cycles in obese adult subjects.

"This approval marks a significant achievement in the clinical development program with oral Oleoyl-estrone," Douglas Abel, Manhattan's CEO said adding, "Given the encouraging early trial results and the large unmet medical need in obesity, we are very pleased to be able to proceed toward patient recruitment and enrolment."

"Oleoyl-estrone is a promising drug candidate and is thought to work both centrally and peripherally," said Alan G. Harris, Manhattan's chief medical officer. "Centrally, it appears to reset the body's ponderostat, the 'food control centre' located in the hypothalamus of the brain that detects and integrates signals controlling appetite and metabolic behaviour. Peripherally, OE appears to cause reduced storage of fat in 'white fat' tissue and allows skeletal muscle to use fat as an alternate energy source," he added.

OE is an orally administered, synthetic form of Oleoyl-estrone, a molecule that exists naturally in the body. Results of the Phase I clinical trials with OE, reported in October 2005, showed the compound was well tolerated. Subjects in the Phase Ib study experienced weight loss as well as beneficial changes in blood glucose and cholesterol levels. There was also evidence of OE offering the potential for sustained weight loss after dosing with OE stopped. Clinical laboratory findings included reversible, dose-dependent elevations in estrone and estradiol levels, as well as reductions in testosterone levels.