For the sixth year in a row, it is time for this column(ist) to share some thoughts on the release of the Lex Machina Patent Report. If any readers want to send me a half-dozen Krispy Kreme donuts to celebrate, I’ll take two each of the glazed, glazed cake, and chocolate iced. Fat and sugar bombs aside, I highly recommend that readers register for the report and give it a read, as there may be more relevant information in it than what follows for any given reader.
As in prior years, what follows are three idiosyncratic takeaways based on my review. First, I’ll skip the usual discussion of the number of district court case filings for a look at what discretionary denial practice has wrought at the USPTO — nothing less than a seismic downward shift in the number of PTAB filings. Second, comparing the report’s observations on the leading plaintiff and defendant law firms in terms of caseload yields some interesting observations. Third, a check in on the Federal Circuit’s handling of appeals from district court cases versus those originating in the PTAB.
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In last year’s review, I mentioned the increase in patent case filings, a trend which continued through 2025. At the same time, perhaps the biggest shift in the relative number of cases filed in any area of law is underway at the PTAB. While the profile of the most active PTAB filers, namely prominent Big Tech companies, has stayed the same, the absolute number of PTAB filings has dropped precipitously in the first half of 2026. We all know the reasons for the drop, but it is still stark to see just how big a decline we are experiencing noted in the report, whereby “201 PTAB petitions, fewer than in any other half-year period in at least a decade” were filed through June in 2026. Contrast that with the modest 8% drop in IPR filings between 2024 and 2025 — with both years seeing over 1,200 IPR petitions filed alone. Even the relatively newfound popularity of PGR petitions, going from 40 in 2024 to 75 in 2025, can change the narrative around PTAB practice in 2026. While the fallout of the drop in filings is still developing, there is no doubt that taking that volume of work from the system will have an impact on both law firm work levels as well as litigation strategies for plaintiffs and defendants. We will see how those changes are reflected in the data when we come to consider next year’s report.
Second, the report’s insights into the most active law firms and attorneys practicing patent litigation on both the plaintiff and defense sides is of interest. To start, only one firm, Delaware’s Morris, Nichols, Arsht & Tunnel, appears on both lists. Given the prominence of that firm in Delaware, as well as the fact that Delaware remains a popular patent venue, the firm’s listing on both lists is understandable. To a certain extent, it also makes sense that a number of prominent Texas local counsel shops find themselves on at least one of the lists, given that Texas maintains strict local counsel requirements and continues to see the most patent cases filed. Nor is it surprising that even amongst the popular choices for Texas local counsel there is an apparent division between firms that appear for plaintiffs as opposed to defendants and vice versa.
Where things get even more interesting, however, is in the consideration of what kind of firms are behind the largest number of patent filings. Even when you take out Isaac Rabicoff of Rabicoff Law’s staggering filing prolificity of over 1,800 cases over the past three years, no less than four other firms have averaged over 100 patent filings per year. And all of the top five, Rabicoff included, are suspected of filing to try to generate quick, low-value settlements for their clients, as opposed to trying to bring cases to trial. Also of note is that in contrast to the list of firms most often tapped to represent defendants — a list that contains at least five Biglaw firms — not a single Biglaw firm has a volume plaintiff’s practice large enough for inclusion. At the same time, we know that a growing ecosystem of boutiques and even Biglaw firms are willing to take select patent cases on the plaintiff’s side, often when the presence of litigation funding is found. Additionally, pharmaceutical patent litigation continues to have a large Biglaw presence on both sides of cases, even as firms segregate themselves on branded versus generic lines in some instances. All in all, it will be interesting to see in the coming years if the lists of most active firms on either the plaintiff or defendant sides, or both, become fluid — or whether the same mix of firms continues to dominate the charts when it comes to volume of cases.
Lastly, the statistics regarding Federal Circuit appeals from patent disputes are interesting. With respect to appeals from district courts, the report concludes that over the 2023 to 2025 period close to 500 patent appeals resulted in a decision on the merits. Of those, only 11% resulted in a straight reversal or clear appellant win, suggesting that the odds of fully overturning a negative result are perhaps overestimated by losing parties. Even when reversals-in-part are included, the report concludes that only a third of Federal Circuit appeals generate an appellant-friendly result. The news is even worse for appellants when it comes to appeals originating from the PTAB. As the report states, “[A]mong the cases resolved by reversal or affirmance, the Federal Circuit affirmed in 601 cases, reversed in 65, and affirmed/ reversed in part in 104. The resulting reversal rate was 22%, with a corresponding affirmance rate of 78%.” Besides for showing a bit more willingness by the Federal Circuit to sign off on outcomes from PTAB tribunals over district courts, the extreme challenge in getting reversals of PTAB decisions confirm why patent owners continue to celebrate the changing landscape at the PTAB, including the drop in IPR filings discussed above.
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Ultimately, the report’s presentation of data confirms yet again that modern patent litigation remains a vibrant and challenging pursuit for both plaintiffs and defendants. It is hard to imagine a more interesting area of law to practice in — it even gets more interesting as experience level increases — and I am grateful for the chance to practice in this profession and practice area. I am sure that many in this readership feel the same way. Thanks once again to Lex Machina for pulling together and presenting the data in a way that highlights how patent litigation is as vibrant as ever.
Please feel free to send comments or questions to me at [email protected] or via Twitter: @gkroub. Any topic suggestions or thoughts are most welcome.
Gaston Kroub lives in Brooklyn and is a founding partner of K2K IP Law, an intellectual property litigation boutique that also serves as a leading consultancy on patent issues for the investment community. Gaston’s practice focuses on intellectual property litigation and related counseling, with a strong focus on patent matters. You can reach him at [email protected] or follow him on Twitter: @gkroub.