The U.S. Court of Appeals for the Federal Circuit determined that a terminal disclaimer cannot be effective if it is filed after the expiration of the earlier patent. The Court determined that the safe harbor provisions of 35 U.S.C. § 121 apply to a divisional of a divisional. Boehringer Ingelheim International GMBH and Boehringer Ingelheim Pharmaceuticals, Inc. v. Barr Laboratories, Inc. and Barr Pharmaceuticals, Inc. and Mylan Pharmaceuticals, Inc. , Case No. 09-1032 (Fed. Cir., Jan. 25, 2010) (Linn, J.; Dyk, J., dissenting-in-part).

Boehringer sued Mylan for patent infringement after being notified by Mylan of an Abbreviated New Drug Application (ANDA) for generic pramipexole. The Mylan case was consolidated with an earlier action against Barr Laboratories. Mylan argued that the asserted claims of the patent in suit, the third in a chain of related patents, were invalid for obviousness-type patenting in view of an earlier issued patent. The district court agreed and held the patent in suit invalid for obviousness-type patenting. During the litigation, Boehringer filed a terminal disclaimer in the patent in suit over the earlier issued patent, which had already expired before the terminal disclaimer was filed. The district court deemed this “retroactive” terminal disclaimer inoperative. The district court also rejected Boehringer’s safe harbor theory of removing another earlier patent as an invalidating reference. Boehringer appealed both points.

In addressing Boehringer’s arguments with respect to the terminal disclaimer, the Federal Circuit noted that the “fundamental reason for the rule [of obviousness-type double patenting] is to prevent unjustified timewise extension of the right to exclude.” Here, Boehringer did not file its terminal disclaimer until long after the earlier patent had expired. The Court reasoned that “[b]y failing to terminally disclaim a later patent prior to the expiration of an earlier related patent, a patentee enjoys an unjustified advantage—a purported time extension of the right to exclude from the date of the expiration of the earlier patent. The patentee cannot undo this unjustified timewise extension by retroactively disclaiming the term of the later patent because it has already enjoyed rights that it seeks to disclaim.”

The Court, however, did overturn the district courts denial of the safe harbor provisions of 35 U.S.C. § 121. The arguments presented centered around the “as a result of” statutory language. The claims of Boehringer’s original application faced a multi-way restriction requirement. The patent in suit was technically a “divisional of a divisional.” The Court reasoned that the safe harbor provision applied because there was “consonance with the restriction requirement” as originally issued, even though the patent in suit included more than one group of the originally -restricted claims. Thus, because the patent in suit honored the lines of demarcation drawn by the examiner in the restriction requirement, the Court concluded that the safe harbor provision applied.

Practice Note: All terminal disclaimers should be filed during the pendency of the parent patent.