Patexia Insight 243: Patent Litigation Trends and Insights from the First Half of 2025

Over the past several years, patent litigation has gone through its share of ups and downs. Shifting legal standards, evolving strategies by patent owners and defendants, and broader economic factors have all played a role in defining the volume and nature of filings. From noticeable drops to signs of recovery, these fluctuations reflect how dynamic the patent enforcement landscape has become.

To better understand where things stand today, we’ve taken a closer look at the latest data across all major forums. Below is a breakdown of new patent litigation cases filed in U.S. District Courts (excluding ANDA litigation) through the first half of 2025.

After holding steady in 2020 and 2021 with just under 4,000 patent cases each year, patent litigation in district courts began to slow. Filings dropped to 3,766 in 2022, then fell more sharply in 2023, which ended with just 3,108 cases, the lowest in recent years. But 2024 showed signs of a rebound, reaching 3,683 cases, driven largely by increased activity in the second half of the year. That momentum has carried into 2025. The first half saw 2,200 new filings, up from 1,721 in H1 2024, a nearly 28% jump. Even the second quarter of 2025 outpaced the first (1,063 cases), keeping the upward trend going. If this pace holds, 2025 could become the busiest year since 2021, pointing to renewed interest in patent enforcement and possible shifts in litigation strategy.

For a deeper dive into long-term trends, key players, and performance metrics, check out our Patent Litigation Intelligence Report, published earlier this year. The report is packed with detailed statistics, interactive charts, and comprehensive rankings of the most active and best-performing law firms, attorneys, companies, and judges involved in patent litigation. Whether you're tracking competitors or refining your litigation strategy, the report offers data-driven insights to support smarter decisions.

ITC Section 337 investigations have somehow mirrored the broader trends seen in District Court litigation over the past years. After peaking at 79 new investigations in 2022, filings dropped to 50 in 2023 before climbing back to 70 in 2024. However, the first half of 2025 has been relatively quiet, with just 30 new filings, a slower start compared to last year, and a possible sign of more selective enforcement or case timing.

For a closer look at the companies, law firms, and attorneys leading in ITC litigation, our ITC Intelligence Report, released earlier this year, offers a comprehensive breakdown. The report includes detailed filing trends, win rates, and exclusive performance rankings that help uncover patterns and key players in this fast-paced venue.

PTAB filings have remained relatively stable over the past few years, with only moderate year-over-year shifts. Inter Partes Review (IPR) activity hovered between 1,300 and 1,400 petitions annually from 2020 to 2022, before dipping to 1,157 in 2023. In 2024, filings rebounded slightly to 1,318, suggesting steady reliance on the PTAB as a venue for challenging patent validity. The first half of 2025 has continued along this line, with 700 IPRs already filed, on pace to match or slightly exceed last year’s total if the trend holds. Other post-grant proceedings have remained limited but steady, with 34 filed in H1 2025.

A more in-depth analysis of these trends, including top petitioners and patent owners, attorneys, law firms, and outcomes, will be available in our PTAB Intelligence Report, set to be released on September 11, 2025. The report will feature detailed statistics, success rates, and performance rankings across all types of PTAB proceedings.

ANDA litigation remained relatively consistent from 2020 through 2023, with annual filings ranging between 246 and 276 cases. In 2024, filings climbed to 317, the highest in five years, signaling renewed activity in the Hatch-Waxman space. So far, 155 cases have been filed in 2025, suggesting that this year may once again see elevated totals if the pace continues through the second half.

To provide deeper insight into these developments, Patexia is currently preparing the 2025 ANDA Litigation Intelligence Report, which will offer comprehensive statistics, performance metrics, and rankings of the most active and best-performing attorneys, law firms, and companies involved in Hatch-Waxman litigation. The report is scheduled for release in the last week of August.

Stay tuned, in the coming weeks, we’ll be sharing more insights from the upcoming ANDA Litigation Intelligence Report, along with updates on patent and trademark prosecution trends from the first half of 2025!