The US Food and Drug Administration (FDA) has held a public hearing on proposals to regulate stem cell treatments in the same way as drugs.
Although some stem cell treatments such as bone marrow transplants are well established, unregulated stem cell clinics offering untested treatments have proliferated in the US because such treatments do not fall under existing regulations (see BioNews 858).
Regulations controlling the use of drugs require advance approval of treatments after the provision of extensive safety and effectiveness data, at a potential cost of millions of dollars to the companies offering these treatments.
But clinics do not need FDA approval if therapies involve 'minimal manipulation' of cells and if those cells fulfil a 'homologous' function similar to their original role in the body. But the precise definitions of 'minimal manipulation' and 'homologous use' are unclear.
A series of four FDA draft guidelines released in 2014 and 2015 addressed that ambiguity by providing concrete examples of what would trigger greater FDA oversight. The FDA held a two-day public hearing on 12 and 13 September to consult on the draft guidelines. It will now decide whether to amend and finalise the proposals.
As many stem cell treatments use cells harvested from the patient's own tissues, it is difficult to determine where control of treatments should lie: the patient has control of their own cells, but may not have sufficient knowledge to correctly judge the risks of what clinics are offering.
'People have the right to decide what happens in terms of the tissues and cells from their own bodies,' said Doug Oliver, a Nashville resident who has macular degeneration told the Washington Post. After treatments at a Florida stem cell clinic, Oliver says his vision improved significantly.
Professor Paul Knoepfler, a stem cell researcher at the University of California, Davis, has been an outspoken critic of unregulated stem cell clinics, and published an article in Cell Stem Cell in July, documenting the extent of the problem. He says there are 570 clinics across the US offering these unapproved procedures, which may put patients at risk. He has called on the FDA to regulate the clinics.
'There is a real risk that as clinics proliferate, if we don't address it in a more proactive way, as we see negative outcomes for patients grow and people get mixed bags of information about stem cells, then this could really negatively impact the public perception of this research,' said Professor Knoepfler. 'The clinics are doing an unapproved and for-profit gigantic human experiment,' he added.
Professor Knoepfler says the FDA must focus on safety. Two patients died after being treated at a Florida clinic, and there have been reports of patients going blind after eye treatments (see BioNews 649). The FDA warns that cells can migrate to the wrong site or could turn into tumours.