Obesity pill shows promise: study

By Michael Kahn
LONDON, 25 oct 2008– People taking NeuroSearch A/S's obesity pill tesofensine lost twice as much weight as men and women using approved weight loss drugs, Danish researchers said on Thursday.
The study suggest the experimental drug is safe because it had no effect on blood pressure and only raised heart rate slightly, said Arne Astrup of the University of Copenhagen, who led the study published in the journal Lancet.
"It is quite solid from this study that it seems to produce a weight loss that is twice ... what we see from existing compounds on the market," Astrup said in a telephone interview.
The company hopes to take tesofensine to Phase III clinical trials early next year -- the last stage of human testing before a company can seek regulatory approval for a drug.
Obesity, which raises the risk of diseases like type 2 diabetes and heart problems, is increasingly a problem as more people adopt a Western lifestyle.
The World Health Organization classifies around 400 million people around the world as obese, representing an increasingly lucrative market for drug makers.
Astrup and his team compared tesofensine against the Sanofi-Aventis SA obesity-fighting drug Acomplia and Abbott Laboratories' Reductil, known as Meridia in the United States.
The 203 obese volunteers at five Danish obesity centers were given different doses of tesofensine or placebo. The drug worked twice as well as previously published data on Acomplia and Reductil, known generically as sibutramine, the study showed.
SIDE EFFECTS
After the study ended, the men and women on tesofensine had lost 10 kilograms more than people on placebo, compared with studies which have shown weight loss of 3 kilograms for Reductil and about 5 kilograms for Acomplia over a similar six month period, Astrup said.
Side effects included dry mouth, constipation and insomnia, but importantly the volunteers did not exhibit the suicidal thoughts that have plagued Acomplia, known generically as rimonabant, Astrup said.
Acomplia took a hit last year when a U.S. expert panel recommended against its approval in the world's biggest market after it was linked to rare cases of suicide ideation -- a psychological problem not shown to raise the risk of suicide but one that worries doctors.
"So far there have been no warnings about problematic side effects," Astrup said. "It seems clean so far."
Other researchers not involved in the study cautioned that the results are from a single trial in a relatively small number of patients.
"We should therefore be a little circumspect about accepting these claims as to efficacy and await the results of the more relevant Phase III studies, which the author does say at the end of the paper," Ian Broom, a researcher at Robert Gordon University in Britain said in a statement.
Tesofensine works by interfering with three brain chemicals -- noradrenline, serotonin and dopamine -- involved in regulating hunger. People who take the pill are less hungry and feel full more quickly.
The next step are Phase III trials in which doctors will also try to regulate diet, something that Astrup said could lead to the kind of weight loss associated with gastric-bypass surgery.
"Most clinicians are always saying we need more effective drugs that can make surgery not necessary," Astrup said. "This is the first opening we have seen."