Companies that find themselves accused of patent infringement in U.S. District Court can face a bewildering array of experiences, all based upon which particular district court they find themselves subject to. After painstaking research, Tokyo-based lawyer Eric D. Kirsch has created the definitive guide to devising a strategy for defending a patent infringement case in the United States. 

Part I.  Introduction 

This paper is written to help companies that are sued for patent infringement (“Patent Challengers”) in the United States. In this paper, I use the term “Patent Challengers” to refer to companies sued for patent infringement, or companies that file Declaratory Judgment actions for non-infringement or invalidity of a patent. Our research shows that there are significant differences in success rates between District Courts for Patent Challengers. What works for a Patent Challenger in Delaware may not work in the Central District of California. Accordingly, companies should be aware of these differences and should take them into account in devising a strategy for defending a patent infringement case in the United States.  

Almost 70 percent of the patent infringement cases in the United States are filed in five District Courts, as shown below in Figure 1. Therefore, we limited our research and this paper to those Top 5 Districts. Understanding which procedural motions and defenses work best for Patent Challengers in these five districts is essential to developing a successful litigation strategy.  

Figure 1 – Top 5 Districts for 2021 for U.S. For Patent Litigation (courtesy of RPX Corp.) 

Based on the data shown in Figure 1, the Top 5 districts for Non-Practicing Entities (NPEs) and operating companies are: the Western District of Texas, the Eastern District of Texas, the District of Delaware, the Central District of California and the Northern District of California.   

In order to provide a comprehensive view of the differences faced by Patent Challengers in the Top 5 districts, we researched outcomes for the following Procedural Motions and Substantive Defenses most often filed by Patent Challengers:  

1. Procedural Motions: 

1. Motions to Transfer for Forum non conveniens. A motion to transfer for forum non conveniens is authorized by statute, specifically, 28 U.S.C. §1404(a).  ;  

2. Motions to Stay Pending an Inter Partes Review, (an Inter Partes Review or IPR is an invalidity proceeding filed in a branch of the U.S. Patent Office called the Patent Trial and Appeal Board, or PTAB);  

2. Substantive Defenses: 

1. Rule 12(b)(6) Motions to Dismiss (based on 35 U.S.C. §101). A Rule 12(b)(6) motion is a procedural device used by defendants to attempt to dismiss a lawsuit before filing an answer.;  

2. Invalidity Summary Judgment Motions (based on 35 U.S.C. §§101, 102, 103 & 112); and 

3. Non-infringement Summary Judgment Motions. 

The success rates for each of these Procedural Motions and Substantive Defenses, in each of the Top 5 districts, is explored and discussed in Part II of this paper, set forth below.  

Our research was optimized in several ways to make the results more meaningful. First, where possible, we limited our research to the years 2018, 2019, 2020 and 2021. In our view, data prior to 2018 risked being stale, as District Court Judges retire, new District Court Judges are sworn in, and motion practice changes over the years. For each district, we generally provided a cumulative percentage to try to smooth out annual variations in success rates for the various motions. Second, we limited the Western District of Texas data to patent cases assigned to Judge Alan Albright, who was sworn in as a District Court Judge on September 18, 2018. Although we did not limit the data from any other district to a single judge, we understand that the vast majority of the Western District of Texas patent cases are filed in the Waco Division, where Judge Albright is the only District Court Judge. Therefore, by choosing to file suit in the Waco Division, plaintiffs are guaranteed that Judge Albright will be assigned to their case. As shown below in Figure 2, Judge Albright currently presides over far more patent cases in the U.S. than any other District Court Judge. 

Figure 2 – Top Judges Overall For 2021 (courtesy of RPX Corp.) 

Therefore, as the vast majority of patent cases filed in the Western District of Texas are assigned to Judge Albright, we believe that analyzing data for cases assigned to Judge Albright is more accurate than analyzing data for cases pending in the entire Western District of Texas.  

Part II.  

What our research shows about the Top 5 patent litigation districts  

Procedural Motions  

Motions to Transfer for Forum non conveniens. If a Patent Challenger is worried about its chances of success in a certain district, it should consider a motion to transfer for forum non conveniens. Patent Challengers have frequently filed these motions in the Western and Eastern District of Texas, with mixed results. Recently, these motions have been the source of a considerable degree of friction between Judge Albright of the Western District of Texas and the Federal Circuit, resulting in an unusual number of mandamus petitions granted by the Federal Circuit. See Extraordinary Writ or Ordinary Remedy: Mandamus at the Federal Circuit – Part 3, https://patentlyo.com/patent/2021/10/extraordinary-ordinary-mandamus-federal-circuit.html (last visited December 21, 2021).  

The data for forum non conveniens transfer motions is set forth below in Figure 3. For a forum non conveniens motion to succeed, there must be a good factual basis to support the motion. The Federal Circuit described these factual bases in In re: Juniper Networks, Inc., Appeal No. 2021-160 (Fed. Cir. Sept. 24, 2021). According to the Federal Circuit, the most important factor is where the witnesses reside. Although the data does fluctuate quite a bit, this is most likely because the data sets for each district are relatively small (often less than 20). Given the small size of the data sets from each district, it is unwise to draw conclusions from annual fluctuations or small numerical differences between districts.    

Figure 3 – Success Rates For Motions To Transfer For Forum non conveniens 

Not surprisingly, the statistics show that it is difficult for Patent Challengers to transfer out of the Western and Eastern Districts of Texas. However, the success rate for transfer motions filed in the Western and Eastern Districts of Texas is somewhat higher if mandamus petitions granted are taken into account. For example, as of October 21, 2021, Judge Albright of the Western District of Texas has had 25 mandamus petitions filed against him in the Federal Circuit challenging his denial of motions to transfer for forum non conveniens. The Federal Circuit has granted and transferred 13 of those cases, which amounts to a 52 percent success rate. Similarly, the Eastern District of Texas has had 63 mandamus petitions filed in the Federal Circuit challenging the denial of motions to transfer for forum non conveniens. The Federal Circuit has granted 18 of those petitions, ordering those cases transferred for a 29 percent success rate. See Extraordinary Writ or Ordinary Remedy, supra at 3.  

Therefore, filing a motion to transfer for inconvenience in the Western or Eastern District of Texas has become a de facto, 2-stage process: (1) file a motion to dismiss before the District Court; and if that motion is denied; then (2) file a mandamus petition before the Federal Circuit. This 2-stage process therefore demands that Patent Challengers make a good factual record in the event a mandamus petition is filed in the Federal Circuit. 

Motions to Stay Pending an Inter Partes Review (IPR). A stay pending an IPR is an important mechanism Patent Challengers can use to defer District Court proceedings and fight invalidity in what most agree is a more favourable forum, the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office. Some districts favour stays to allow IPRs to proceed, while other districts mostly refuse to stay cases for IPRs. The data for stay motions (pending an IPR) for the Top 5 districts is set forth below in Figure 4.  

Figure 4 – Motions to Stay Pending IPR, courtesy of Docket Navigator 

As indicated in Figure 4, the Northern District of California is generally the most favourable district for a Patent Challenger to file a motion to stay pending an IPR, while the Eastern District of Texas is least favourable. At this time, it is unclear whether Judge Albright’s very recent willingness to stay cases pending an IPR is a new trend or not. 

The 88 percent figure for 2021 in the Western District of Texas includes two sets of related cases. The first set of cases is comprised of five related patent cases; the other set is comprised of two related patent cases. All seven cases were stayed by Judge Albright in December of 2021. 

Substantive Defenses 

Rule 12(b)(6) Motions To Dismiss For Lack of Patentable Subject Matter. Filing a Motion to Dismiss for Lack of Patentable Subject Matter (pursuant to 35 U.S.C. §101) is a popular Patent Challenger strategy mainly because, depending on venue, these motions have a decent chance of success and they save significant time and money because they are filed before discovery and claim construction begin. However, the success of these motions largely depends on two factors: (1) whether the Plaintiff-Patent Holder is an NPE or not (as shown in Figure 5 below); and the district where the case is pending (see Figure 6 below). 

Figure 5 – §101 Motions Nationwide (as of 3-31-2021), courtesy of RPX Corp. 

Although the data may seem promising for Patent Challengers, particularly where the Patent Holder is an NPE, the win rates vary widely by district, as shown below in Figure 6.  

Figure 6 – §101 Motion Win Rate By District, courtesy of Docket Navigator 

With respect to Rule 12(b)(6) motions to challenge patentability, Judge Albright of the Western District explained that “because a patent is presumed valid and requires clear and convincing evidence to provide its invalidity, a Rule 12(b) motion to dismiss is a procedurally awkward place for a court to resolve a patent’s §101 eligibility.” Slyce Acquisition Inc. v. Syte-Visual Conception Ltd., No. 6:19-cv-257-ADA, 2020 WL 278481 at *5 (W.D. Texas Jan. 10, 2020). Judge Albright further explained that “because resolving §101 eligibility of all asserted claims almost certainly requires fact discovery and because fact discovery does not begin until after claim construction under the Court’s default Order Governing Proceedings, the Court believes it is wiser and more efficient to wait to determine a patent’s §101 eligibility until after fact discovery has opened.” Id. at *6. On December 27, 2021, Judge Albright granted his first Rule 12(b)(6) dismissal under §101. It is too soon to tell if this is a new trend or an aberration for Judge Albright.  

In addition, §101 motions have lost some of their effectiveness due to the Berkheimer and Aatrix cases, as shown below in Figure 7. In the Berkheimer and Aatrix cases, the Federal Circuit held that questions of fact concerning patentability under §101, raised by the Patent Holder, may preclude granting a §101-based Rule 12(b)(6) motion.  

Figure 7 – Pre/Post Berkheimer Motions Rule 12 and Summary Judgment, courtesy of RPX Corp. 

Therefore, although §101 motions are not quite as effective as they once were, the substantial benefits (an early win while avoiding the burden and expense of discovery and claim construction) makes them worth considering, particularly in the Northern and Central Districts of California. 

Invalidity Summary Judgment Motions (§§101, 102, 103 & 112). Summary judgment motions are generally a Patent Challenger’s preferred way to dispose of a case on the merits. As shown in Figure 8, most patent cases disposed of on the merits are decided by summary judgment. For example, in 2020 68 percent of all patent cases that did not settle were disposed of by summary judgment. Therefore, Patent Challengers should carefully consider summary judgment success rates in the Top 5 districts.  

Figure 8 – Nationwide Merits Dispositions, courtesy of RPX Corp. 

An invalidity summary judgment motion is one of the primary defensive weapons held by a Patent Challenger. As with the other defenses discussed here, the success rate of an invalidity summary judgment motion varies widely among the Top 5 patent districts. The data we compiled on invalidity summary judgment motions includes all of the invalidity defenses, namely, invalidity under 35 U.S.C. §§101, 102, 103 and 112. 

Figure 9 – Invalidity Summary Judgment Success Rates By District, courtesy of Docket Navigator 

Unlike motions to transfer or stay, invalidity summary judgment motions can be granted partially, in other words, the court might find some patent claims invalid and other patent claims not invalid. Therefore, certain year columns contain two percentages: the percentage on the left is where all of the patent claims that were the subject of the summary judgment motion were invalidated; the percentage on the right represents the success rate if partial summary judgment rulings are included (i.e., only some of the claims were invalidated). According to Figure 9, for Patent Challengers, it appears that the Eastern District of Texas is the most difficult district for wining an invalidity summary judgment motion, while the Central District of California is the least difficult district for wining an invalidity summary motion.  

Non-Infringement Summary Judge Motions, Along with invalidity summary judgment motions, non-infringement summary judgment motions are another important defensive tool for Patent Challengers, so we naturally researched the success rate for non-infringement summary judgment motions in each of the Top 5 patent litigation districts. The results of our research are shown below in Figure 10.  

Figure 10 – Non-Infringement Summary Judgment Motion Success Rate 

Just as with invalidity summary judgment, partial summary judgment of non-infringement had to be taken into account. For the year columns, the percentage on the left represents the success rate if all of the claims that were the subject of the summary judgment motion were held not infringed, while the percent on the right includes partial summary judgment of non-infringement, in other words, only some of the claims were held not infringed.   

According to our research, the Western District of Texas is the most difficult district to win a non-infringement summary judgment motion, while the Northern District of California is the least difficult district to win a non-infringement summary judgment motion.  

Part III. Conclusion 

From a Patent Challenger’s viewpoint, the differences between the Top 5 patent litigation districts are substantial, both for Procedural Motions and Substantive Defenses. Generally speaking, Procedural Motions and Substantive Defenses are more difficult to win in the Western and Eastern Districts of Texas, and easier to win the Central and Northern Districts of California. Accordingly, as these win rates are public information, many Patent Challengers attempt to transfer out of the Western and Eastern Districts of Texas.  

However, defending a case in the Northern and Central Districts of California has downsides that Patent Challengers should be aware of. For example, complying with all of the disclosure rules in Northern District of California makes litigating there more expensive. In addition, defending a case in the Northern and Central Districts of California means that fact discovery begins immediately after the Scheduling Conference, while fact discovery is deferred in the Western District of Texas. Therefore, defending a case in the Northern or Central Districts may initially be more expensive than defending a case in the Western District of Texas. Patent Challengers should be aware of the additional cost of defending a case in the Central or Northern Districts of California before deciding to file a motion to transfer to one of these Districts. In our experience, most Patent Challengers are willing to pay the additional cost of defending a patent case in the Central or Northern Districts of California in exchange for the increased chances of success.