The market share price of the pharmaceutical company Vivus has soared after the company published promising results from its late-stage clinical trial into the new diet pill Qnexa.
The medication is a combination of two drugs, the epilepsy medication called topiramate and the weight-loss drug phentermine. This was previously a popular diet pill but fell out of favour with doctors and specialists after effectiveness and safety concerns.
The Phase III trials showed that patients taking the medication lost a significant proportion of their body weight and also showed a reduction in their blood pressure, likelihood of developing type 2 diabetes and fat levels.
The trials were randomised. One involved 1,267 morbidly obese patients and the other involved 2,487 patients who were overweight or obese and had other health problems like diabetes or high blood pressure.
After a year of taking part in the trial, patients taking the medication at the highest dose lost 10.4% of their body weight on one trial and 11% on the other, compared with 1.6% to 1.8% amongst those taking the placebo. After taking into account the placebo effect this added up to weight loss of 9%, well surpassing the 5% the FDA demands for approval for a new diet pill to be approved.
Further FDA benchmarks were met when 70% of patients taking the drug lost at least 5% of their body weight, compared to 20% taking the placebo. The FDA say that at least twice as many patients taking a medication as those taking a placebo must lose at least 5%. However about 40% of those taking the high dose did not complete the year of treatment so this could be significant.
Vivus, based in California, say they plan to ask for FDA approval next year. We are not sure at this stage if the company is going to seek approval in the EU as phentermine has had a problematic history with the European Medicines Agency.