Opinions — Tuesday, April 28, 2026

In Taiho Pharmaceutical Co., Ltd. v. MSN Laboratories Private Ltd., Nos. 2025-1407, 2025-1453, the Federal Circuit dismissed the appeals upon joint stipulation of the parties under Federal Rule of Appellate Procedure 42(b), with each side to bear its own costs. The court noted that it generally does not specify whether a dismissal is with or without prejudice, notwithstanding the parties' request for dismissal with prejudice.

The Federal Circuit vacated-in-part and affirmed-in-part a final judgment following a jury trial in the Eastern District of Texas where Constellation Designs, LLC obtained a verdict against LG Electronics Inc., LG Electronics USA, Inc., and LG Electronics Alabama, Inc. for willful infringement of claims directed to non-uniform signal constellations in digital communication systems across four patents: U.S. Patent Nos. 8,842,761, 10,693,700, 11,019,509, and 11,018,922. The court vacated the district court's summary judgment of eligibility under 35 U.S.C. § 101 for claims 17, 21, 24, and 28 of the '761 patent and claim 5 of the '700 patent—claims reciting a "geometrically spaced symbol constellation optimized for capacity using parallel decode capacity"—but affirmed the eligibility determination for claims 21 and 23 of the '509 patent and claims 24 and 44 of the '922 patent, which recite specific non-uniform constellations with particular point locations. The court affirmed the denial of LG's motion for judgment as a matter of law of non-infringement and the denial of its motions challenging damages and the admissibility of Constellation's damages expert testimony.

The decision's significance lies in its differential treatment of patent eligibility for process-oriented optimization claims versus claims reciting specific constellation designs, even where both claim categories derive from the same underlying inventive approach of optimizing constellations for parallel decode capacity rather than maximum minimum distance (d_min). By vacating the eligibility finding for the optimization claims while affirming eligibility for the constellation claims, the court signals continued scrutiny under § 101 of claims directed to iterative optimization processes involving known techniques—here, the patentee's named inventor conceded that neither the communication system hardware, non-uniform constellations, nor optimization of non-uniform constellations for specific characteristics was invented by the patentees, and the prior art disclosed optimizing constellations for parallel decode capacity. The remand on eligibility for roughly half the asserted claims creates substantial uncertainty for Constellation's damages award and underscores the continuing instability of § 101 doctrine where claimed inventions involve applying optimization techniques to known system parameters, particularly in standards-essential technology contexts.