An experimental study of a new weight loss drug known as Tesofesine, has been shown to be twice as effective as other weight loss medications on the market.  Tesofesine, which works as an appetite suppressant, showed that in a study of 161 participants, the average weight loss over a 6 month study was between 3 – 13kg, depending on the dosage of the drug.  

Funded by Danish biopharmaceutical company Neurosearch in the hope of using testofesine as a weight loss drug, studies were carried out at University of Copenhagen.  Researcher and university MD, Arne Astrup said “Normally the drugs now on the market give you at best a weight loss of 5 kilograms (11 pounds) with diet and exercise. In this study we doubled that weight loss."

Tesofensine, which has previously been studied to treat Alzheimer’s and Parkinson’s disease, showed limited efficacy in treatment for these diseases, but significant weight loss in trial participants who were obese.  It works by affecting three different appetite regulatory centres of the brain, in the form of neurotransmitters noradrenaline, dopamine and serotonin.  

Reported in The Lancet (Oct. 22, 08) the phase II placebo controlled study included obese patients, weighing around 100 kilograms.  They were put on a calorie restricted diet and asked to exercise over 30 minutes a day.  Patients had either a placebo, 0.25, 0.5 or 1 milligrams of tesofesine.

The phase III study is set to take place in both the US and Europe and assuming positive trials, the drug is hoped to reach market within 4 years. Patients on the 1 milligram dose tended to have an increase in blood pressure relative to placebo and as such phase III trials will concentrate on the effectiveness of a 0.5 milligram dose.  

There are still important questions regarding the safety of the drug.  Thomas Wadden, PhD, at the University of Pennsylvania School of Medicine Centre for Weight Loss and Eating Disorders said that “blood pressure finding is particularly troubling”. Patients taking the tesofesine also reported more anger, hostility and confusion compared to placebo participants.