Novo Nordisk has received a boost with the publication of data from a mid-stage trial which shows that its type 2 diabetes drug liraglutide is more effective than Roche's Xenical in terms of weight loss and reducing blood pressure.

The Novo-sponsored 564-patientPhase II study, the data for which have been published in The Lancet, assessed the effect of liraglutide on bodyweight and tolerability in obese individuals without type 2 diabetes. Researchers from the University of Copenhagen, report that after 20 weeks, patients taking one of four doses of the Novo drug lost between 4.8-7.2kg while also exercisng and dieting. This compared to 4.1kg for patients on Xenical (orlistat) and 2.8kg for those in in the placebo group.

The researchers also noted that liraglutide reduced blood pressure at all doses, and reduced the prevalence of prediabetes (84%–96% reduction) with 1·8-3·0mg per day. Nausea and vomiting occurred more often in individuals on liraglutide than in those on placebo, “but adverse events were mainly transient and rarely led to discontinuation of treatment,” they added.

Liraglutide is an injectable human glucagon-like peptide-1 (GLP-1) analogue and its weight-lowering properties have been well-established in a number of trials. The drug was approved for diabetes in Europe in July and is being marketed as Victoza, but the company is still waiting for the green light in the USA.

The diabetes indication is comfortably the most important one for Novo at the moment but the weight loss market is a lucrative one. A number of drugs of failed such as Sanofi-Aventis' Acomplia (rimonabant), which was pulled from the market over the risk of psychiatric adverse effects, including suicide and seizures, and Merck's taranabant. Both of those treatments block cannabinoid type 1 receptors in the brain.

Back to the GLP-1 analogues and in an accompanying editorial in The Lancet, George Bray from Louisiana State University’s division of clinical obesity and metabolism, wrote that “whether long-term use of an injectable drug is palatable as a treatment for obesity is yet to be established”. However, he added that “from what we do know about GLP-1 agonists and their mechanisms, we can be optimistic that their promise for the treatment of obesity will be fulfilled”.

However Roche and GlaxoSmithKline, which markets a lower-dose, over-the-counter formulation of orlistat, sold as Alli, are confident that their products will continue to dominate the weight loss market, They noted that the Novo study only used one dose of Xenical and also the latter has the advantage of being an oral treatment.