In G.D. Searle LLC v. Lupin Pharms, Inc., No. 14-1476 (Fed. Cir. June 23, 2015), the Federal Circuit revisited the ongoing litigation between Pfizer and generic drug makers over certain drug patents for treatment of pain and inflammation. The Court previously invalidated Pfizer’s patent for obviousness-type double patenting over an earlier-issued patent, finding that 35 U.S.C. § 121’s safe harbor provision did not apply to Pfizer’s asserted patent, which derived from a continuation-in-part, not a divisional as required by statute.

Deleting new matter not present in the common application and designating its application as a divisional of the original application, Pfizer sought and had reissued its invalidated patent. It then sued generics for infringement.

On appeal, the Court held again that § 121 does not apply to shield the reissue patent. The Court concluded that the reissue patent was not a divisional because deleting new matter did not retroactively alter its lineage as a continuation-in-part. The Court also held that the reissue patent did not issue from the same restriction requirement as the earlier-issued patent. Because the Court held that the § 121 did not apply, the Court did not reach the question of whether the reissue patent was validly reissued.