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Federal Circuit applies interference time limitsJuly 17, 2006

The Federal Circuit recently decided an issue regarding in an interference proceeding between The University of California against The University of Iowa. Iowa holds a patent on a method of minimizing allergic reactions in subjects exposed to allergens. California had a pending application dealing with related technology. Seven months after the Iowa patent issued, California added claims to its application in an effort to provoke an interference with Iowa’s patent. (An interference is an administrative proceeding where the Patent Office decides who, between two or more inventors, was the first to invent a claimed invention and therefore is entitled to a patent.) An interference was not declared at that time because the added claims did not satisfy the written description requirement. California eventually cancelled these claims because of this rejection. More than one year after Iowa’s patent issued, California added another claim that did result in an interference with Iowa’s method claim. The Board of Patent Appeals and Interferences found that California could not assert its claim against Iowa’s patent because it was added more than one year after Iowa’s patent issued. California also could not rely on the filing date of its earlier claims to meet the one year requirement because the new claim was materially different from those prior claims. On appeal, California argued that the Board’s interpretation of the relevant statute was incorrect. The statute bars any claims from being added to a pending application that are ‘for the same or substantially the same subject matter as, a claim of an issued patent’ unless the claims are added within one year after the patent issued. California argued that because it filed claims that satisfied this statute (the seven month claims), the statute did not bar its claim filed more than one year later to provoke the interference, even though its additional claim wwas materially different from the earlier claims. The Federal Circuit disagreed based on precedent, the plain meaning of the statute, and policy. First, earlier Federal Circuit cases have already held that a claim added more than a year after a patent issued must not differ in any ‘material limitation’ from a claim on file within the allowed time frame. Second, the structure of the statute makes it clear that a claim added to provoke an interference must be added prior to one year from the date on which the patent was granted, not some other, prior claim. Third, the policy behind the statute is to place a time limit on a patentee’s exposure to potential interference proceedings. This policy would be undermined if applicants could discharge their obligation under the statute simply by filing a claim that would cause an interference within one year, even if that claim is not otherwise patentable. This case emphasizes that if an applicant wishes to provoke an interference proceeding, any claims required to bring about the interference must be added no more than one year after the issue date of the patent containing similar claims. Otherwise, any claims added after one year cannot materially differ from claims added prior to the one year mark in order to preserve the right to participate in the interference. To read the complete decision, log on to

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