Our Patent Case Summaries provide a weekly summary of the precedential patent-related opinions issued by the Court of Appeals for the Federal Circuit and the opinions designated precedential or informative by the Patent Trial and Appeal Board.
NCS Multistage Inc., et al. v. Nine Energy Service, Inc.
No. 2025-1000 (Fed. Cir. (W.D. Tex.) Sept. 14, 2026). Opinion by Cunningham, joined by Reyna and Hughes.
NCS sued Nine Energy Service for infringement of a patent related to a tool used in the oil and gas industry to assist with inserting a long strip of pipe (the “casing” or “casing string”) to the bottom of a wellbore. The district court construed several claim terms, and the case proceeded to trial. A jury returned a verdict for NCS, finding certain claims infringed and not invalid. The district court then denied Nine’s post-trial motions, and Nine appealed.
The Federal Circuit vacated the judgment of infringement and remanded for a new trial. To begin, the Federal Circuit ruled that the district court erred in construing “internal diameter” to refer to “both an inner surface and a measured diameter.” The Federal Circuit held that, properly construed, the “internal diameter” is a “measured diameter” across the width of the casing string. The court explained that the intrinsic evidence “does not clearly require ‘internal diameter’ to have two different meanings,” and the prosecution history “is not sufficiently clear to override the presumption that claim terms carry the same meaning throughout the patent.”
Next, the Federal Circuit ruled that the district court erred in construing “casing string” to include a size limitation (≥ 4.5 inches in outer diameter). The Federal Circuit observed that “the specification repeatedly refers to a casing string without any size limitation, instead describing it by its function.” Also, while it was undisputed that 4.5 inches is a common size, the specification “explicitly states that it is not limited to any particular size of casing string.”
Turning to validity, Nine argued that a third party’s sale of a device embodying the claimed invention to Apache before the patent’s priority date, and Apache’s subsequent use of that device, constituted prior art. NCS countered that its own earlier sale of a device to Tundra embodying the claimed invention was a “public disclosure” under 35 U.S.C. § 102(b)(1)(B), which prevented the third party’s later sale to Apache from constituting prior art.
The Federal Circuit relied on precedent to conclude that “no reasonable jury could have found that the sale of the [device] to Tundra was a public disclosure.” The device “was privately sold to a single party (Tundra),” and there was no evidence that the device was “widely distributed or placed where the public could examine them.” As a result, the later sale to Apache, and Apache’s use of that device, qualified as prior art. The Federal Circuit thus vacated the judgment of no invalidity and remanded for a new trial.
TexasLDPC Inc. v. Broadcom Inc., et al.
No. 2025-1074 (Fed. Cir. (D. Del.) Sept. 14, 2026). Opinion by Chen, joined by Moore and Bissoon (sitting by designation).
TexasLDPC, the exclusive licensee of certain asserted patents and copyrights, sued Broadcom and others for infringement without joining the patent owner (Texas A&M University) as a co-plaintiff. After years of litigation, the district court dismissed the lawsuit on two grounds: (1) TexasLDPC’s license agreement had automatically terminated during the litigation when TexasLDPC shifted from commercialization to enforcement-only operations, and (2) even if the agreement had not terminated, the lawsuit could not proceed without joinder of A&M.
The Federal Circuit reversed because, under the license agreement, “TexasLDPC has not ceased its business operations, and thus the Agreement did not terminate when TexasLDPC shifted its business to enforcement.” Also, “the Agreement conveyed ‘all substantial rights’ in the asserted patents to TexasLDPC, thereby entitling TexasLDPC to sue for infringement in its own name.” Because A&M was not otherwise a necessary party under Federal Rule of Civil Procedure 19(a), the Federal Circuit reversed the district court’s dismissal.
The Federal Circuit’s analysis focused on three main disputes: (1) interpretation of the license agreement, (2) whether TexasLDPC held all substantial rights such that it could sue in its own name without joining A&M as the patent owner, and (3) whether Rule 19(a) requires joinder of A&M as a necessary party.
First, applying the rules of Texas contract law, the Federal Circuit agreed with TexasLDPC that the license agreement did not terminate due to TexasLDPC ceasing its business operations by shifting to enforcement-only activity. The agreement explicitly included enforcement as a type of “business operations.” And several provisions in the agreement demonstrated that it “unambiguously contemplates enforcement as one of TexasLDPC’s business operations.”
Next, the Federal Circuit agreed with TexasLDPC that it holds “all substantial rights” to bring the lawsuit against the defendants without joining the patent owner. The court emphasized that TexasLDPC holds the exclusive rights to make, use, sell, and sublicense the patented products, and has “the first and only right to enforce” the patents and copyrights against third parties. A&M’s retained rights—including the right to practice the patents for research and education, the sole right to enforce it against a single prior licensee, and the right to approve assignment of the agreement—were not individually or cumulatively substantial enough to preclude TexasLDPC from bringing suit alone.
Finally, the Federal Circuit held that A&M was not a necessary party under Rule 19(a) “for the same reasons we used to determine TexasLDPC possesses all substantial rights to the patents-in-suit.” “Because A&M has transferred ‘all substantial rights’ in the asserted patents to TexasLDPC, its absence does not ‘impair or impede’ A&M’s ability to protected its interest …, nor does it leave Defendants ‘subject to a substantial risk of incurring double, multiple or otherwise inconsistent obligations.’”