Threat lifted: Alzheimer's patients stand to benefit from research with the Mayo Foundation's mice. Credit: CATHERINE POUEDRAS/SPL

Neuroscientists worldwide can continue to enjoy access to an important transgenic mouse used for research into Alzheimer's disease, following the rejection of a patent-infringement claim against the institution that distributes the mice.

Elan Pharmaceuticals, Inc., based in Ireland, filed a suit against the Minnesota-based, non-profit Mayo Foundation for Medical Education and Research last year, alleging that two of its US patents for transgenic mice were being infringed by the foundation's strain of transgenic mice (see Nature 404, 319–320; 2000). If successful, the move could have blocked the Mayo Foundation's distribution of the mice.

But on 15 June, Judge William Alsup of the US District Court in San Franciso dismissed Elan's lawsuit. He ruled that the company's two patents were invalid, as they involved technology already included in an earlier patent that the Mayo Foundation was licensed to use.

“This is really fantastic news,” says Steve Younkin, a neuroscientist at Mayo's facility in Jacksonville, Florida, where its Alzheimer's research is concentrated.

Elan intends to appeal against the decision. “We are confident the patents are valid and the court will reverse the decision,” says Libby Murphy, Elan's executive vice-president for intellectual property and legal affairs. An Elan spokesman adds, “It is unfortunate we have to defend our intellectual property against the Mayo Foundation, as we have worked closely with them in the past and hope to do so in the future.”

The Mayo Foundation's transgenic mice were developed and distributed using technologies licensed from the University of Minnesota and a small Kansas company, the Alzheimer's Institute of America.

Judge Alsup ruled that the Alzheimer's Institute's technology, patented by neuroscientist Michael Mullan of the University of South Florida (see right), preceded Elan's patent disclosures. “The Mullan patent application disclosed the same recipe for making transgenic mice as was later disclosed in the [Elan] patents,” Alsup wrote in his eight-page ruling.

Karen Boyd, the Mayo Foundation's attorney with the law firm of Fish & Richardson, says the court ruling “gives researchers at the Mayo Foundation, other academic institutions and biotechnology companies the opportunity to continue research”.

The transgenic mice of both organizations are different, but they both involve engineering the mice to have a human genetic mutation that is linked to a build-up of amyloid protein leading to neurodegeneration in the brain.

The Mayo Foundation has been distributing its mice to academic institutions at nominal costs, although it has been charging some pharmaceutical companies as much as $850,000 for a breeding group.

Elan is known for exerting tight control over the distribution of its products to academic researchers and other drug companies.

Two disputed patents were acquired when Elan purchased Athena Neurosciences, Inc. in 1998. If the court ruling stands after Elan's appeal, the two patents would be permanently invalidated, and the US Patent and Trademark Office would withdraw them. A decision by an appeals court in Washington usually takes a year.