In Wyeth v. Kappos (Appeal No. 2009-1120), the U.S. Court of Appeals for the Federal Circuit affirmed a decision of the U.S. District Court for the District of Columbia (Wyeth v. Dudas – Civil Action No. 07-01492) finding that the U.S. Patent and Trademark Office (USPTO) had misconstrued the law governing calculation of patent term adjustments for prosecution delays, therefore denying the patent holder a portion of the patent term to which it was entitled. In view of this case, it may be possible for other U.S. patent holders to obtain lengthened patent terms through a petition to correct the Patent Term Adjustment determined under the USPTO’s prior incorrect calculation.

The term of a patent changed in 1994 from 17 years from issuance to 20 years from filing, regardless of prosecution delays. A prosecution delay would thereby unfairly shorten a patent’s effective term. As a result, in 1999 Congress enacted the American Inventors Protection Act, 35 U.S.C. § 154(b), to allow a patentee to recoup certain periods of a USPTO-imposed prosecution delay.