By Ewen Callaway of Nature magazine

Procedures that involve human embryonic stem cells cannot be patented, the European Court of Justice declared today.

Oliver Brüstle, director of the Institute of Reconstructive Neurobiology at the University of Bonn, Germany, who had a patent on a method for generating neurons from human embryonic stem cells rejected by the court, called the ruling "the worst possible outcome", and "a disaster for Europe".

He and other scientists worry that the ruling will cause European companies and scientists to miss out on commercial applications for embryonic-stem-cell research.

Early-stage trials of embryonic-stem-cell therapies for macular degeneration--progressive damage to the retina that causes blindness--are already under way. Scientists believe that embryonic stem cells could also be useful for treating neurodegenerative diseases and diabetes, among other conditions.

"The saddest part is the bad news it brings for young people in the field, because 90% of them went into this to make a difference in biomedicine and to develop therapies. What can we say to them? It will be difficult to persuade them to stay in Europe," says Brüstle.

Broad ban

The court's ruling, which cannot be appealed and applies to all 27 member states of the European Union (EU), bans patents on procedures that involve the destruction of human embryos at any stage. That includes not only procedures in which embryonic-stem-cell lines are created, but also those that use previously derived cell lines.

"I think there's very little room for interpretation," says Clara Sattler de Sousa e Brito, a patent attorney who argued Brüstle's case in front of the 13 judges of the European court's Grand Chamber.

The court's decision does not come as a surprise. In March, advocate general Yves Bot issued a preliminary judgment limiting patents involving embryonic stem cells, on the basis that they "would be contrary to ethics and public policy" (see 'European Court of Justice rejects stem-cell patents').

But in banning patents on procedures that use extant stem-cell lines, the Grand Chamber's ruling goes a step further, says Brüstle. The court ignored statements in favor of such patents from the European Commission and several EU countries, including the United Kingdom, Sweden, Portugal and Ireland.

Unwelcoming climate

Existing European patents involving embryonic stem cells--most of which were issued in the United Kingdom--will not be invalidated immediately, but lawsuits challenging individual patents will use the ruling as guidance. "The patents don't vanish but they're practically unenforceable," says Sattler de Sousa e Brito.

She says the ruling also seems to apply to procedures that do not involve the destruction of embryos because it bans patents that use embryos as "base materials". However, Huw Hallybone, a patent attorney at Carpmaels and Ransford in London, reads the ruling to exempt non-destructive methods. "My own views is that if you can make human embryonic stem cells without destroying the embryo, it would be patentable," he says.

This debate is more than an academic one. Advanced Cell Technology, based in Santa Monica California, is developing embryonic stem cell therapies for macular degeneration and other conditions using cells obtained non-destructively from an early embryo called a blastocyst. Robert Lanza, the company's chief scientific officer, says the ruling won't affect his company, but adds: "I think this is the kiss of death for companies using destructive methods to generate stem cells."

Ian Wilmut, a stem-cell biologist at the MRC Centre for Regenerative Medicine in Edinburgh, UK, says that a lack of patent protection could reduce the willingness of European companies to invest in treatments based on stem cells. He worries that the ruling could foster an unwelcoming climate that would eventually trickle down to limit funding for basic research on embryonic stem cells.

Embryonic stem cells could potentially be replaced in therapies by induced pluripotent stem (iPS) cells--adult cells that have been reprogrammed to an embryonic-like state. But the methods used to reprogram cells can damage their DNA, and the iPS cells may not behave in exactly the same way as embryonic stem cells.

"From the point of view of patients, we have to hope that the alternative methods will come along and prove to be equally effective. We don't know that yet, but we have to hope for it," says Wilmut.

Alex Denoon, a solicitor specializing in intellectual-property rights at Lawford Davies Denoon in London, says that the ruling is "unwelcome because it causes uncertainty". But he notes that long-standing uncertainties surrounding European patents of techniques based on embryonic stem cells have meant that scientists and their attorneys are used to coming up with workarounds to protect discoveries.

Global hope

In the United States, scientists face few restrictions on patents of embryonic-stem-cell applications. In 2008, the US Patent and Trademark Office upheld three stem-cell patents held by the Wisconsin Alumni Research Foundation in Madison that had been challenged on the grounds that they were excessively broad and stifled research.

With companies able to protect their patents in the United States and elsewhere, and competitors unable to easily create generic and knock-off embryonic-stem-cell treatments, the impact of the European ruling on investment and therapeutic development should be blunted, says Denoon.

Peter Coffey, a stem-cell biologist at the Institute of Ophthalmology in London, is developing an embryonic-stem-cell treatment for macular degeneration with the global drug company Pfizer. Clinical trials for the therapy could begin next year. The relevant patents involve the positioning of differentiated retinal cells in the eye and not the creation of these cells and would potentially be exempt from the ruling; his team wrote its patent this way to distinguish it from other stem-cell-based applications--they felt that describing the placement of cells rather than the creation of the cells was likely to be more novel. But, he says, "the fact that you're having to develop a workaround is not good; it does not give confidence to an investor".

This article is reproduced with permission from the magazine Nature. The article was first published on October 18, 2011.