Appeals Court Bars EST Patent

Eli is a contributing correspondent for Science magazine.

In a landmark ruling on the patentability of genetic material, a federal appeals court yesterday said that bits of DNA that bind genomic sequences of unknown function cannot be patented. Academic and industry scientists had feared a ruling allowing the patent--applied for by agrobiotech giant Monsanto in 2000--would set a low bar for patenting genetic material, allowing endless DNA patents that could hinder basic research.

Scientists use small bits of DNA called expressed sequence tags, or ESTs, to bind to larger DNA fragments and find new genes. Monsanto had sought a patent for five ESTs that bound to DNA in corn leaves. In 2001, a Patent and Trademark Office (PTO) examiner rejected the innovations as unpatentable because they lacked a " 'real world' context of use." The case went to a PTO review panel and then to the appeals court, where Monsanto argued that several applications--including finding DNA regulatory regions called promoters--made the ESTs useful.

But in its decision yesterday, the U.S. Court of Appeals for the Federal Circuit said that Monsanto needed to lay out more "specific" uses--the identification of particular promoters, for example. "The claimed ESTs themselves are not an end of [Monsanto's] research effort, but only tools to be used along the way," wrote the court in a 2-1 decision. The decision does not bar other patents on ESTs, experts say; it simply demands more specific applications.

The case is the latest effort by the courts to clarify whether scientific discoveries whose use may not be fully clear may be patented or not. In a brief in support of the PTO, the National Academy of Sciences and several biotech companies argued that granting the EST patent could chill research by creating widespread fears of infringement suits. "Had we lost this [case], there would have been a flood" of patents granted for other ESTs, says Joseph Keyes, a lawyer with the Association of American Medical Colleges, also a part of the brief.

St. Louis, Missouri-based Monsanto says that the decision provides needed "clarity" but hasn't decided whether it will request a rehearing with the appellate court. The decision could benefit Monsanto by lowering the chance that the company would be sued for infringement for using ESTs in its own laboratories; the company says it pursued the patent in the first place to assess that risk.

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