By Ben Hirschler
LONDON (Reuters) - An experimental drug that mimics the effects of two naturally occurring hormones appears to work significantly better than existing single-hormone medicines against diabetes and obesity, scientists said on Wednesday.
A team of German and U.S.-based researchers said they are using "mother nature's toolkit" to seek a breakthrough for treating type 2 diabetes and related obesity which is affecting rapidly growing numbers of people in the West and many developing nations.
The new dual-action molecule, which is being developed by Swiss drugmaker Roche, targets receptors for hormones known as GLP-1 and GIP that play a critical role in regulating the body's metabolism.
Currently approved injectable drugs such as Novo Nordisk's Victoza and Byetta from Bristol-Myers Squibb and AstraZeneca mimic only GLP-1.
By addressing two hormones at once, researchers said the new molecule was more potent and could be administered at lower doses, reducing side effects such as nausea and vomiting that are associated with GLP-1 drugs and can limit their use.
The new drug was assessed in a short clinical study involving 53 obese patients with type 2 diabetes, as well as in laboratory studies on mice, rats and monkeys.
In all these cases the scientists found a synergistic effect from combining the GLP-1 (glucagon-like peptide-1) and GIP (glucose-dependent insulinotropic polypeptide).
"We are using mother nature's toolkit and we're hoping to find the right combination that will produce a breakthrough," researcher Matthias Tschoep of the Institute for Diabetes and Obesity at the Helmholtz Zentrum in Munich told Reuters.
"I believe a combination of things will be necessary to reach the efficacy and power to really cure and prevent type 2 diabetes and obesity."
Tschoep and colleagues are also investigating combining other hormones involved in metabolism and insulin release in a single drug.
The Munich team, working with scientists from Indiana University, detailed the advantages of the new GLP-1/GIP drug in a paper in the journal Science Translational Medicine.
The experimental molecule proved considerably more effective than existing medications in controlling blood glucose levels and reducing weight. In some of the tests, the impact of the dual-action treatment was equivalent to that seen with a 10-fold higher dose of approved GLP-1 drugs.
The clinical trial involving obese patients, which was conducted by Roche, produced a strong reduction in blood glucose levels - but the six-week study was not long enough to give a definitive result on weight loss in humans.
While there were no serious side effects in the clinical trial, a few patients did some experience nausea.
Current GLP-1 drugs are expected to rack up global sales of $2.9 billion in 2013, a figure that is forecast to rise to $6.9 billion by 2018 as more products enter the market, according to consensus estimates compiled by Thomson Reuters.
Roche acquired rights to the new product after buying Marcadia Biotech in 2011 and currently has the drug in Phase I development. A company spokesman declined to comment further on plans for the medicine.
Drugmakers are competing fiercely in the type 2 diabetes market as the number of people with the disease continues to grow rapidly. Finding successful treatments for obesity is proving difficult, however, and sales of various types of weight-loss drugs have been disappointing.
Novo Nordisk has been testing high doses of its GLP-1 drug as an obesity treatment but a number of analysts have questioned whether it will produce a big enough effect to be a commercial success.
(editing by David Stamp)