Two US public interest groups have asked a federal appeals court to hear a challenge of a patent over human embryonic stem cells (hESCs).

Consumer Watchdog, a non-profit consumer advocacy organisation based in Santa Monica, California, along with lawyers from the Public Patent Foundation (PPF), lodged an appeal from a decision by the US Patent and Trademark Office (USPTO) to uphold the patent, assigned to the Wisconsin Alumni Research Foundation (WARF).

The patent is over three claims to in vitro cultures of hESCs based on the research of Professor James Thompson, who is listed as the sole inventor.

Consumer Watchdog's opening brief claims that WARF’s patent 'has put a severe burden on taxpayer-funded research in the state of California'. It states the patent patent 'gives WARF the potential to completely preempt all uses of hESCs, including particularly for scientific and medical research'.

The groups initially challenged the three patents held by WARF in 2006 through a process called re-examination. During this process, third parties can ask the USPTO to revoke a patent. Although they were initially successful at having the patent declared invalid, the USPTO later upheld the patent, albeit with some changes.

The appeal brief cites the US Supreme Court ruling in Association for Molecular Pathology v. Myriad Genetics, where the court struck down a patent for the BRCA gene on the basis that genes cannot be patented.

Consumer Watchdog claims that the nature of the patents at issue are too broad and that 'such broad claims to products of nature are not patent eligible'. It asserts that the patent claims cover hESCs that are 'not markedly different from naturally occurring hESCs'.

'WARF did not create or alter the properties inherent in stem cells any more than Myriad created or altered the genetic information encoded in the DNA it claimed', the brief states.

Dr Jeanne Loring, director of the Center for Regenerative Medicine at the Scripps Institute has also been involved in supporting Consumer Watchdog and PPF since the beginning of the legal process. 'This is an important battle. hESCs hold great promise for advancing human health, and no one has the ethical right to own them', she said.

WARF declined to comment on the challenge, saying that it needs to review the filing with its attorneys, GenomeWeb reported on Wednesday. Carl Gulbrandsen, director of WARF, has previously called the Myriad ruling 'unfortunate', saying it threatened to invalidate the existing patents of important medical products and could discourage research on future genetically-based medical therapies.

SOURCES & REFERENCES