Countries should unite to tackle unscrupulous advertising of unproven therapies involving stem cells, experts say.
An international group of leading experts has called for tighter regulation of so-called stem cell tourism. This involves patients travelling to other countries, where medical regulations are less strict, for treatment with potentially unsafe therapies.
Hundreds of medical centres around the world are offering therapies that involve transplantation of so-called stem cells -- which they claim have the ability to repair damaged tissues. Clinics are marketing the treatment for a range of conditions, including multiple sclerosis and Parkinson's disease.
Often these therapies are advertised directly to patients with the promise of a cure. But experts say there is often no evidence to show that the treatments will help anyone, or will not cause harm.
Researchers say the practice risks undermining the development of rigorously tested, validated therapies and puts lives at risk.
Writing in the journal Science Translational Medicine, the group has called for coordinated global action to tackle the problem.
They say tighter regulations on advertising stem cell therapies are needed, so that unsupported claims about potential clinical benefits do not go unchallenged.
Global regulatory authorities should agree international standards for the manufacture and testing of cell and tissue-based therapies, they add.
The group -- which includes experts from the University of Edinburgh -- also calls for the World Health Organization to help guide responsible clinical use of cells and tissues, as it does for medicines and medicinal devices.
Their appeal follows the deaths of two children at a clinic in Germany in 2010, which exploited a legal loophole to offer untested treatments. The clinic has since been closed.
Dr Sarah Chan, a Chancellor's Fellow at the University of Edinburgh, said: "Many patients feel that potential cures are being held back by red tape and lengthy approval processes. Although this can be frustrating, these procedures are there to protect patients from undergoing needless treatments that could put their lives at risk.
"Stem cell therapies hold a lot of promise but we need rigorous clinical trials and regulatory processes to determine whether a proposed treatment is safe, effective and better than existing treatments."
Some types of stem cell transplantation - mainly blood and skin stem cells -- have been approved to treat certain types of cancer and to grow skin grafts for patients with severe burns. These treatments have been rigorously tested in clinical trials.
Advice about the current state of research and risks associated with unproven stem cell therapies is available from the EuroStemCell website http://www.eurostemcell.org.
Science Translational Medicine