Armstrong Teasdale

Armstrong Teasdale LLP is a full-service BigLaw firm headquartered in St. Louis, Missouri, with a substantial footprint of over 600 lawyers and business professionals across 18 offices internationally. The firm consistently ranks among the top legal practices, appearing at #181 in the 2026 AmLaw 200. Chambers USA has recognized Armstrong Teasdale's Intellectual Property practice for its depth of resources and ability to handle complex mandates.

The firm's Intellectual Property Litigation team is highly experienced in enforcing and defending patent, trademark, copyright, and trade secret rights. They cover a broad spectrum of technologies, including electrical, computer, mechanical, aerospace, chemical, biochemical, and biotechnical engineering. Specific areas of expertise span from medical devices, software, and electronic voting machines to industrial chemicals, earth-moving machinery, and advanced materials like silicon wafers. This wide technical breadth allows them to represent diverse clients, from inventors and manufacturers to universities and multinational corporations.

Armstrong Teasdale actively engages on both the plaintiff and defendant sides of patent disputes, reflecting a balanced approach to litigation. The firm's internal records show appearances for both plaintiffs and defendants. For example, the firm represented the defendant in the case Kubota North America Corporation et al. v. Vermeer Manufacturing Co. Publicly, they achieved a notable $12 million jury verdict for a software and consulting company in a patent infringement case related to physician efficiency. They have also secured dismissals of substantial infringement claims and successfully defended against patent and copyright allegations.

The firm also maintains a robust practice before the Patent Trial and Appeal Board (PTAB) at the U.S. Patent and Trademark Office (USPTO). Their PTAB team represents both patent owners and petitioners in post-grant proceedings, including inter partes review (IPR), post-grant review (PGR), and derivation proceedings, leveraging these as strategic alternatives or parallels to district court litigation.

Key partners in the IP litigation practice include James M. Heinen, Jr., who leads the Intellectual Property practice group. Richard L. Brophy is frequently highlighted for his patent infringement litigation expertise and is recognized by Chambers and IAM. Other prominent IP litigation partners include Christopher Goff and Patrick Rasche, also recognized by Chambers for their intellectual property work, and Marc W. Vander Tuig, a key contact for post-grant proceedings.