These Firms Are Picking up the Most PTAB Work

Jason Fitzsimmons, director and co-chair of Sterne Kessler’s Patent Trial and Appeal Board (PTAB) practice, discussed Lex Machina’s latest patent litigation report with Law360. Sterne Kessler was ranked among the top six firms for PTAB trial activity from 2023 to 2025 with 184 trials.

Fitzsimmons attributed the increase in the firm’s PTAB trials during that period in part to its experience before the PTAB, which has undergone significant changes that have created uncertainty for clients and practitioners, “I think that uncertainty has perhaps driven some clients to some of the firms with the most experience historically at the PTAB.”

With the recent changes at the PTAB, many patent challengers are now leaning on ex parte reexaminations. Fitzsimmons noted Sterne Kessler’s extensive reexamination practice, which predates the PTAB, “I think that has continued to serve us well because that is one of the more important decisions that clients are making right now: which forum is best suited for their challenge and where they are most likely to have success,” he said. “Clients continue to rely on us for those fact-intensive assessments.”