Debevoise & Plimpton LLP has secured a victory in a patent litigation case before the Court of Appeals for the Federal Circuit on behalf of GAF Materials LLC against Kirsch Research and Development, marking the end of a multi-year, multi-venue, multi-patent and multi-defendant campaign.

In 2020, in a variety of federal courts, Kirsch sued GAF and a dozen other global roofing manufacturers, alleging they were infringing Kirsch patents that covered roof underlayment products. On the same day, Kirsch also launched a patent infringement investigation with the U.S. International Trade Commission (ITC) against GAF and others to block them from continuing to sell their products in the market.

At the ITC, Debevoise, along with counsel for the other parties, successfully argued for a specific claim construction, which asserted that the patent infringement allegations were unfounded, especially since GAF’s roof underlayment products were not 100% polypropylene – a different material than Kirsch’s roofing products. The arguments were successfully adopted by the ITC, leading Kirsch to dismiss its own ITC investigation.

After losing the ITC investigation, Kirsch returned to the district courts to proceed with its only remaining patent. In response, Mr. Neukom filed an inter partes review (IPR) petition challenging the validity of Kirsch’s remaining patent before the Patent Trial and Appeal Board (PTAB). After reviewing the firm’s forceful arguments, the Board invalidated every single patent claim asserted by Kirsch, thereby vindicating not only GAF, but all the other defendants. That win was shouted out in AmLaw’s Litigator of the Week column.

Kirsch then moved to appeal the PTAB’s decision in the Federal Circuit Court of Appeals last year. Earlier this year, Debevoise took the podium and argued to the Federal Circuit. On May 2, the appeals court agreed with the firm’s persuasive arguments, upholding the PTAB's decision. The court agreed that the claims in the patent were not new or innovative because they were already covered by prior art, which is existing knowledge in the field. The appeals court also awarded GAF its costs on appeal. This significant win marks the ending to a long and hard fought patent litigation case in the construction industry.

The Debevoise team was led by litigation partner Jay Neukom.