Nastech's PYY3-36 nasal spray aims to deliver the natural, appetite-regulating hormone PYY directly to the bloodstream. The hope is that it will improve on current treatments such as Roche's Xenical (orlistat) and Abbott's Reductil (sibutramine), which are held back by side effects and limited efficacy.
The Phase I study involved 37 clinically obese individuals who received three daily doses of either PYY3-36 nasal spray or placebo, one hour before each meal for eight consecutive days. Subjects receiving PYY had a reduction in 24-hour calorie intake compared to placebo that started immediately following treatment and continued to decrease over the six treatment days of the study.
They also recorded a weight reduction of 1.3 pounds over the course of the study, and experienced an average 6 per cent reduction in serum cholesterol levels.
PYY is a naturally occurring hormone that physiologically inhibits food intake. PYY is produced by specialised endocrine cells (L-cells) in the gut after a person eats and is believed to trigger the feeling of satiety, to reduce appetite and to decrease food intake through modulation of appetite circuits in the brain, specifically involving the Y2 receptor.
In 2004, the US Centre for Disease Control and Prevention ranked obesity as the number one health threat in America. It is the second leading cause of preventable death in the US and the American Obesity Association estimates that approximately 127 million, or 64.5 per cent, of adults in the U.S. are overweight and an estimated 60 million, or 30.5 per cent, are obese.
The total direct and indirect costs attributed to overweight and obesity amounted to $117 billion (€96 billion) in 2000. Additionally, Americans spend more than $33 billion (€27 billion) annually on weight-loss products and services.