We have a number of overweight patients being treated very successfully with Xenical, which is a lipase inhibitor and works locally in the gastrointestinal tract to prevent the digestion and therefore the absorption of fats. A number of patients who try the medication find that they want to stop taking it after one month as they experience unfortunate side effects such as loose bowel movements and an urgent need to have a bowel movement. This patient compliance issue means that patients do not achieve the results that they desired as they are not prepared to continue with the treatment if they have to endure the side effects. (It should be pointed out that for most people, these side effects disappear with an adjustment to diet and most people do not actually get the side effects.) However, there is a new drug in development with Alizyme – a UK biotech company – which works in a very similar way to Xenical and seems to have similar weight loss results but with relatively few patient compliance issues. The phase IIb trials demonstrated that it had 90% fewer patient compliance issues when compared with Xenical.
The new drug, known as Cetilistat, is being prepared for phase III trials. This is a potentially very exciting development as it is not always possible to prescribe the currently available alternatives to Xenical as they are both centrally acting so are therefore not appropriate for a large number of patients. Having this alternative treatment, which acts peripherally, will be very important for the therapeutic treatment of overweight patients.
Given that Alizyme has not yet announced details of when the next phase of the trials will commence, we are not expecting the drug to come to the market any time soon and we estimate that it could be as late as 2009.