Acomplia was a ground-breaking new breed of medication which targeted the body’s little understood endocannabinoid system when it was launched in the UK last June but it could soon have one or more rivals. Both Merck and Pfizer have similar drugs in Phase III clinical trials which are said to be producing very promising results. Merck has already announced that it intends to apply for regulatory approval in 2008 and it is believed that Pfizer will be aiming to seek approval at around the same time. There is another drug which works in a similar way to Acomplia under development by Bristol Myers Squibb but it is believed that the development of this product is significantly behind those of Merck and Pfizer.
The drugs in development are all CB1 receptor antagonists. Results from the trials have not yet been published so it is not possible to gauge whether they will have a better success rate than Acomplia. What is known is that the slimming pill under development by Merck is going to be of a much lower dosage than the 20 mg at which Acomplia is licensed in the UK. The Phase II trial focused on 6mg, 4mg and 2 mg strengths but the Phase III trial will focus on 2mg, 1mg and 0.5mg, suggesting that the company has either concluded that a lower dose is better or the side effects were too severe at the higher dosages.
Although the endocannabinoid system is not fully understood, it is believed to form part of the body’s system of regulating cravings. Samples taken from obese women have been compared with samples taken from lean women and the level of endocannabinoids found to be much higher in the obese women. This discovery has led scientists to conclude that the endocannabinoid system is likely to be overactive in obese people. The introduction of Acomplia, which prevents the CB1 receptor from working, has helped thousands of obese patients in the UK to lose weight.