As more and more people fight obesity, drug makers are trying to find solutions to help them. This is what drug developer Vivus Inc hopes to achieve with its experimental drug Qnexa. Obese patients treated with the highest dose of the drug lost on average 9.2 percent of their weight.

Qnexa is a combination of phentermine- half of the recalled fen-phen diet pill – and the epilepsy drug Topamax, or topiramate.

The finding is based on study involving 756 patients. Those taking the highest dose of Qnexa lost the most weight, compared with patients who took the drug’s individual components and those who took a mid-dose or placebo pill.

The participants were required to eat no more than 500 calories a day and to exercise at least three times a week.

Vivus said the drug was well-tolerated – the most common side effects were itching, dry mouth, altered taste and constipation. The company expects results in mid-2009 from two larger Phase III trials of Qnexa and plans to file for US Food and Drug Administration approval late next year. Qnexa is also studied as a treatment for diabetes, but the company needs to conducts a study of how the drug compared with phentermine and topiramate before it can launch a Phase III diabetes trial.

Obesity is one of the main health problems of the world, with 400 million obese people classified by the World Health Organisation around the world. Obesity is also a significant risk factor for a number of chronic diseases such as heart disease and type 2 diabetes, but efforts are done in order to better understand the factors that contribute to this health condition.