Leydig, Voit & Mayer

Leydig, Voit & Mayer is a Chicago-headquartered intellectual property boutique with a century-long history in the field. The firm maintains five offices across the U.S. (Chicago, Alexandria, Boulder, and San Francisco Bay Area) and Germany (Frankfurt), along with a presence in Shenzhen, China. With over 80 attorneys and patent agents supported by 100 staff professionals, Leydig is recognized for its focused expertise in intellectual property law. Chambers USA has lauded the firm as "the quintessential, time-honored patent firm" and "top-notch and cost-effective," while Best Law Firms® has awarded Leydig national first-tier rankings in Patent Law, Trademark Law, and Patent Litigation.

The firm's IP litigation practice spans a broad array of technology areas, including biotechnology, chemical technologies, cybersecurity, electrical, computer, and software technologies, internet and telecommunications, mechanical, electromechanical, and optical technologies, and pharmaceuticals and biosimilars. Leydig's litigators possess diverse technical and industry backgrounds, enabling them to handle complex patent infringement, trade secret, trademark infringement, and unfair competition disputes.

Leydig demonstrates experience representing both plaintiffs and defendants in patent litigation. The firm acted as lead counsel for the plaintiff in Walker Digital, LLC v. Microsoft Corp. et al., a case where a Federal Circuit opinion affirmed non-infringement against Microsoft in 2014. Conversely, Leydig served as lead counsel for the defendant OnePlus Technology (Shenzhen) Co., Ltd. in Pantech Corporation et al. v. OnePlus Technology (Shenzhen) Co., Ltd. In this case, a jury in the Eastern District of Texas found in March 2024 that OnePlus willfully infringed five of Pantech's patents related to wireless communication and user interface technologies, awarding Pantech over $10 million in damages. However, a Texas federal judge subsequently ordered a new trial for damages, finding the jury's award excessive and ruling that OnePlus did not infringe one of the patents.

The firm also possesses a robust Post-Grant Proceedings practice before the U.S. Patent and Trademark Office (USPTO). Leydig attorneys are experienced in inter partes review (IPR), post-grant review (PGR), covered business method patent reviews, and ex parte reexaminations, offering strategic counsel to both patent owners and those facing infringement allegations.

Key partners in Leydig's intellectual property litigation practice include H. Michael Hartmann, who was individually recognized by Chambers USA, and Christopher James Gass, both noted for their roles as lead counsel in tracked cases. Other prominent IP litigation partners from firm information and Super Lawyers lists include Gregory Bays and Aaron R. Feigelson.