The U.S. Court of Appeals for the Federal Circuit (CAFC) recently made a significant ruling regarding patent law. The court decided that a “first-filed, first-issued, later-expiring claim cannot be invalidated by a later-filed, later-issued, earlier-expiring reference claim” under the doctrine of obviousness-type double patenting (ODP). This ruling came in response to a case involving Allergan USA Inc. and Sun Pharmaceutical Industries Limited.
The dispute centered around claim 40 of U.S. Patent 7,741,356, which covers “eluxadoline tablets” used to treat irritable bowel syndrome with diarrhea (IBS-D). The district court initially ruled that claim 40 was invalid due to ODP and that other claims by Allergan were invalid for lack of written description.
However, the CAFC reversed these decisions, emphasizing that the purpose of ODP is to prevent patentees from extending the life of a first patent by obtaining a second patent on a similar invention. The court clarified that ODP should not be used to block a first-issued patent that expires later than another patent.
In its ruling, the CAFC also addressed the distinction between patent term extension (PTE) and patent term adjustment (PTA) in ODP analysis. The court highlighted that ODP analysis should focus on the expiration date of a patent after PTA has been added, rather than just the filing or issuance dates.
Furthermore, the CAFC rejected the argument that a later-issued but earlier-expiring patent could invalidate an earlier-issued but later-expiring patent, emphasizing that the priority date and filing order are crucial factors in determining ODP.
Regarding written description, the CAFC found that the district court had erred in its interpretation and reversed the conclusion that the claims were invalid for lack of written description. Judge Dyk dissented on this point, supporting the district court’s decision.
Legal experts and practitioners have reacted positively to the CAFC’s ruling, noting that it will protect many pharmaceutical patents that have received PTE and PTA. They believe that the decision clarifies ODP law and provides stability for patent holders in the pharmaceutical industry.
Despite the positive reception, some experts feel that the ruling could have gone further in addressing certain aspects of ODP law. They hope that the Federal Circuit will consider further clarifications or revisions to ensure consistency and coherence in future ODP cases.
Overall, the CAFC’s decision in the Allergan case has significant implications for patent law and the pharmaceutical industry. It provides important guidance on ODP analysis and highlights the complexities involved in determining patent validity based on expiration dates, priority dates, and patent issuance order.