A court decision on 23 July could help to tame the largely unregulated field of adult stem-cell treatments. The US District Court in Washington DC affirmed the right of the Food and Drug Administration (FDA) to regulate therapies made from a patient’s own processed stem cells. The case hinged on whether the court agreed with the FDA that such stem cells are drugs.

The judge concurred, upholding an injunction brought by the FDA against Regenerative Sciences, based in Broomfield, Colorado. Under the treatment sold by the firm, stem cells are isolated from patients’ bone marrow, processed, and the resulting cells injected back into the patients to treat joint pain. The FDA calls this pro­cedure the “manufacturing, holding for sale, and distribution of an unapproved biological drug product”, and in August 2010, ordered Regenerative Sciences to stop offering the treatment (see Nature 466, 909; 2010).

During investigations leading up to the injunction, the FDA also found that, because of flaws in its cell processing, the company was violating regulations on “adulteration” that are meant to ensure patients’ safety.

Jeanne Loring, a regenerative-medicine scientist at the Scripps Research Institute in La Jolla, California, says that the decision will send a warning to other entrepreneurs offering unapproved stem-cell treatments. “So many people want to start these companies. They say, ‘FDA? What FDA?’.”

Chris Centeno, the medical director of Regenerative Sciences and one of two majority shareholders, told Nature that he plans to appeal against the ruling. During the case, the company claimed that the cells in its ‘Regenexx’ procedure are not significantly modified before they are reinjected, so the procedure should be considered routine medical practice. The company also argued that because all the processing work is done in Colorado, the procedure should be subject to state law, rather than to regulation by the FDA.

The court disagreed on both counts, noting that “the biological characteristics of the cells change during the process”, and that this, together with other factors, means the cells are more than “minimally manipulated”.

“Maintaining the FDA’s role as watchdog and regulatory authority is imperative.”

Leigh Turner, a bioethicist at the University of Minnesota in Minneapolis, agrees. “It is much too simplistic to think that stem cells are removed from the body and then returned to the body without a ‘manufacturing process’ that includes risk of transmission of communicable diseases,” he says. “Maintaining the FDA’s role as watchdog and regulatory authority is imperative.”

Centeno says that the FDA injunction applies to only one of his company’s four stem-cell products — one that requires 4–6 weeks of processing. The procedure will still be available: after the 2010 injunction, the company moved its treatment location to an affiliated Cayman Island clinic.

Centeno plans to continue providing the other three procedures, also used for joint pain, in the United States. In those treatments, the cells are reinjected within two days. Centeno claims that those cells are “minimally manipulated”, and that the FDA sees them as the “practice of medicine” and “has no issues” with them. Indeed, until 25 July, a graphic on the Regenerative Sciences website claimed that these three procedures were “FDA approved”.

In fact, the FDA has not approved these procedures, and Centeno did not provide documentation to support his claims that the agency views the three treatments as outside its purview. The graphic was removed after Nature’s enquiries.

Doug Sipp, a stem-cell ethics and regulation expert at the RIKEN Centre for Developmental Biology in Kobe, Japan, worries that more stem-cell companies might now set up shop outside the United States to avoid regulation, as Regenerative Sciences has done. “Other US stem-cell outfits have close ties with partner clinics in Mexico and other neighbouring countries, which are traditionally regulatory havens for other forms of fringe medicine as well. I suppose it will be business as usual in such places,” Sipp says.