Patexia Insight 246: What the Latest Data Reveals About ANDA Litigation Trends

Abbreviated New Drug Application (ANDA) litigation remains one of pharma’s most contested arenas. With market exclusivity and billions in annual sales on the line, each case influences competition, pricing, and the speed at which patients see lower-cost alternatives. Our latest ANDA Litigation Intelligence Report 2025 sheds light on these dynamics with a comprehensive review of 1,373 cases filed from July 1, 2020, through June 30, 2025, and 1,892 patents involved. In this article, we focus on one of the central aspects of the report: filing activity. We look at how ANDA case filings have evolved year by year, where the peaks and dips occurred, and what these trends reveal about the broader dynamics of Hatch-Waxman litigation.

Between the second half of 2020 and mid-2025, the volume of cases remained relatively steady, with 2024 marking a peak of 317 new filings, the highest in the study period. There were 130 filings in the second half of 2020, followed by 246 cases in 2021. Filings increased to 263 in 2022 and held largely steady at 262 in 2023. During the first half of 2025, 155 cases were filed, suggesting that overall activity remains consistent, although the final full-year figure is yet to be determined.

The annual trend in patents litigated largely parallels case filings, though with some variation in magnitude. The number of patents at issue rose from 490 in 2021 to a peak of 650 in 2022, then declined to 552 in 2023 before recovering to 614 in 2024. In the first half of 2025, 313 patents have already been challenged, pointing to a continuation of strong activity for the year.

These patterns underscore the dual dynamics of Hatch-Waxman litigation: while the number of cases signals market entry efforts from generic firms, the volume of patents highlights how brands defend exclusivity across formulations, methods, and manufacturing processes.

Analyzing filings on a monthly basis provides a clearer picture of activity, helping to account for the uneven length of half-year periods. Case filings averaged around 20–22 per month from 2020 through 2023, before jumping to 26.4 per month in 2024 and sustaining at 25.8 per month in the first half of 2025. This uptick reflects continued pressure on blockbuster drugs and steady efforts by generics to expand market access. Patent challenges per month display more volatility. The ratio of patents per case peaked at 2.47 in 2022, signaling more complex disputes, before moderating closer to 2.0 in 2025. These swings highlight how brand companies often rely on layered portfolios and multiple patents to deter or delay generic entry.

For readers seeking a deeper dive, the full ANDA Litigation Intelligence Report 2025 offers comprehensive insights beyond filing trends. The report examines the most frequently litigated technologies, court-level patterns, and the outcomes of these disputes. Furthermore, the report provides full rankings of the companies, law firms, and attorneys driving ANDA litigation activity, with activity and performance metrics broken down by role, plaintiff, defendant, and overall. We also highlight notable lateral moves over the past 12 months since our previous ANDA report, showing which law firms gained or lost ground as a result. In addition, the report offers detailed insights on all judges participating in these cases. In total, the study covers 137 judges, 471 companies, 1,574 attorneys (including 235 local counsel), and 200 law firms, providing a comprehensive view of the stakeholders in ANDA litigation.

Read the full report here.