U.S. Intellectual Property Practice
YMF Law is built around one proposition: that the most sophisticated IP matters benefit from senior trial talent assembled specifically for the matter, not from whoever is available on a firm roster. Whether York serves as lead counsel with a supporting team, or as a senior member of a team led by another designated counsel, the client works directly with York — not a relationship partner managing work performed by others. The assembled team is drawn from available market talent and matched to the jurisdiction, technology, and strategic demands of the specific matter.
That model is possible because YMF Law is an independent senior partner practice. There is no firm roster to draw from and no institutional billing structure to satisfy — which means no associate layer, no cross-office conflicts, and no organizational constraints on the advice. For clients who have retained large firms and found the senior talent inaccessible after engagement, the structure resolves the problem directly.
Patent Litigation
District Court · International Trade Commission · Post-Grant Proceedings
Patent litigation is the center of the YMF Law practice — thirty years of it, across the full range of technology sectors, in federal courts from Washington D.C. to Los Angeles. The cases have ranged from single-patent disputes to multi-front global litigation coordinated across the U.S., Japan, Europe, and Asia. The common denominator is not the technology. It is the level: complex, high-stakes, matters where the outcome is consequential.
District Court
Federal district court patent litigation is where most matters are tried and where YMF Law's trial practice is centered. York has appeared in district courts nationwide — from the Eastern District of Virginia and the District of Delaware to the Northern and Southern Districts of California, and venues across the country. The full jurisdiction list is at the bottom of this page.
International Trade Commission
Section 337 investigations at the ITC present a distinct procedural environment: accelerated schedules, an Administrative Law Judge presiding over an evidentiary hearing, and a remedy — exclusion from U.S. importation — unavailable in district court. York has litigated ITC matters across multiple technology sectors, including matters involving Japanese companies on both sides of a Section 337 proceeding.
The ITC's Japan dimension is notable: Japanese manufacturers and exporters are frequent respondents in Section 337 investigations, and Japanese companies bringing enforcement actions increasingly use the ITC's exclusion remedy as a complement to or substitute for district court relief. York's ITC practice experience and Japanese language capability are directly relevant to both postures.
Post-Grant Proceedings - PTAB
Inter partes review, post-grant review, and covered business method proceedings before the Patent Trial and Appeal Board are now standard features of complex patent litigation — initiated offensively to cancel asserted patents, or defensively to manage concurrent PTAB and district court proceedings. Post-grant strategy is integrated into the overall litigation approach from early case assessment through appeal.
Hatch-Waxman / Life Sciences / ANDA / Biosimilars
Pharmaceutical patent litigation · Paragraph IV proceedings · BPCIA biosimilar pathway
A Career Emphasis Within the Patent Practice
Pharmaceutical patent litigation under the Hatch-Waxman Act has been a defining strand of the YMF Law practice since York's earliest years in civil litigation. Paragraph IV ANDA proceedings, Orange Book listed patent disputes, 30-month stays, and the strategic interplay between FDA regulatory timelines and litigation posture are not a specialty acquired alongside a general patent practice. They are the work York has done at the highest level for three decades.
Representations have included brand pharmaceutical companies defending against paragraph IV challenges by generic companies seeking to establish invalidity or non-infringement of listed patents. The drug brands that have been at issue include Crestor®, Paxil®, Prozac®, Doribax®, Zymar®, Engerix-B®, Infranrix®, Adenoscan®, Adenocard®, Veralix®, and AmBisome®, among others.
Biologics litigation under the Biologics Price Competition and Innovation Act (BPCIA) — the biosimilar pathway that mirrors Hatch-Waxman for biologic drugs — is a natural extension of this practice. The BPCIA's 'patent dance' procedures, exclusivity periods, and FDA approval pathway create a litigation environment closely analogous to Hatch-Waxman ANDA proceedings.
Japanese pharmaceutical companies have been consistent clients in this practice. The combination of Hatch-Waxman litigation depth, Japanese language capability, and direct relationships with Japanese pharmaceutical legal and business teams means that YMF Law can serve Japanese pharmaceutical clients in U.S. ANDA proceedings without the translation layer that characterizes most cross-border pharmaceutical engagements. Client communication, document review, and strategic consultation happen in Japanese, at the level of technical and legal complexity these matters require.
Co-author: FDA薬事規制と医薬品特許権侵害訴訟 (FDA Pharmaceutical Regulation and Drug Patent Litigation — A Guidebook for U.S. Drug Development), the leading Japanese-language publication on FDA regulation and Hatch-Waxman litigation.
IP-Related Antitrust
Patent misuse · Standard-essential patents · Reverse payment settlements
Antitrust issues arise at the intersection of intellectual property rights and competition law — and in IP litigation, they arise often. The YMF Law antitrust practice is not a general competition practice. It is the antitrust dimension of IP litigation: patent misuse defenses raised in infringement actions, standard-essential patent and FRAND licensing disputes, and the antitrust scrutiny that attaches to reverse payment settlements in paragraph IV Hatch-Waxman proceedings.
Reverse payment settlements — in which a brand pharmaceutical company compensates a generic challenger to delay market entry — have faced sustained antitrust challenge since the Supreme Court's Actavis decision. For brand and generic pharmaceutical clients navigating the terms of a paragraph IV settlement, the antitrust exposure is not theoretical. It is a litigation risk that must be assessed at the settlement table, not discovered afterward.
Warning Letters
Infringement notices · Demand letters · United States and Japan
An infringement warning letter (警告状) is rarely just a letter. It is the opening position in a negotiation that may become litigation — and how it is drafted, how it is received, and how the recipient responds establishes the strategic posture of everything that follows. The threshold question of whether to send a warning letter, and on what terms, is a litigation strategy decision as much as a drafting exercise.
For Japanese companies receiving U.S. infringement demands, early consultation — before a response is sent — is often the most consequential intervention available. The response to a warning letter can shape venue selection, litigation posture, and settlement leverage in ways that are difficult to reverse once established. YMF Law evaluates the demand, assesses the claim on the merits, and advises on response strategy.
Due Diligence
Litigation due diligence · Patent validity and enforceability · Transactional IP assessment
Patent due diligence examined from a litigation perspective asks a different set of questions than prosecution-focused analysis: not only whether the patents are valid on their face, but whether they will hold up under the claim construction, prior art, and damages arguments that an adversary will advance. That assessment requires the judgment of a lawyer who has been on both sides of those arguments in court.
Pre-suit due diligence for potential patent plaintiffs involves infringement claim mapping, freedom-to-operate analysis, validity risk assessment, and an honest evaluation of damages exposure and likely forum. For companies on the receiving end of a threatened suit, the same analytical framework applied to the asserted patents determines whether the exposure is real and what the settlement range looks like.
Transactional due diligence — for M&A, licensing, investment, or acquisition of patent assets — requires the same litigation-tested analysis applied to the portfolio as a whole. For Japanese companies acquiring U.S. patent assets or entering licensing arrangements with U.S. patentees, the due diligence assessment is available in Japanese, covering both the U.S. litigation risk profile and the strategic value of the assets under U.S. market conditions.
IP Counseling & Strategic Claim Analysis
Strategic IP counseling · Claim analysis for litigation readiness · Infringement and validity assessment
Strategic IP counseling is the work that precedes and shapes litigation — the ongoing assessment of a client's IP position, competitive landscape, and legal exposure that determines when to enforce, when to license, when to challenge, and when to settle. For clients who are not yet in litigation but are operating in patent-intensive markets, that assessment is as consequential as anything done in court.
Strategic claim analysis examines existing patent claims — whether the client's own or those of an adversary — through the lens of how they will perform under litigation conditions. Claim construction risk, prosecution history estoppel, written description and enablement vulnerabilities, and the realistic scope of protection after claim narrowing are the questions that matter in court. That analysis informs licensing negotiations, enforcement decisions, and portfolio management with the precision that litigation experience provides.
For Japanese companies monitoring U.S. patent enforcement activity — tracking competitor patent issuance, assessing freedom to operate in U.S. markets, or evaluating the strength of patents they hold or have licensed — YMF Law provides strategic IP counseling in Japanese. The analysis is grounded in how U.S. courts actually adjudicate these questions, not in how they read in the abstract.
Portfolio Management
Patent portfolio strategy · Prosecution oversight · Litigation readiness assessment
Patent portfolio management viewed from a litigation perspective asks a different question than prosecution-focused portfolio management: not only whether patents issue, but whether they will hold up and perform under litigation conditions. York's portfolio counseling is informed by three decades of litigating patents that were well-drafted and patents that were not — and by the direct experience of watching claim construction, validity challenges, and damages calculations determine the difference between an enforceable portfolio and an expensive one.
For Japanese companies with U.S. patent portfolios, portfolio management counseling is available in Japanese and covers both the prosecution strategy questions (what to file, where, and how to draft for U.S. litigation performance) and the strategic IP landscape questions (where competitor patent activity creates enforcement risk or opportunity). The goal is a portfolio that performs when it matters.
Patent Monetization & Sale
Patent assertion · Licensing strategy · Patent acquisition and sale
Patent monetization — assertion, licensing, and sale of patent assets — converts IP holdings into business results. The decision to assert, license, or sell a patent or portfolio is a strategic and legal judgment that depends on an accurate assessment of what the assets are worth under litigation conditions, what the enforcement landscape looks like in the relevant technology and venue, and what the counterparty's exposure and negotiating position actually are.
Patent acquisition — for defensive portfolio building or offensive assertion — requires the same litigation-tested analysis applied to assets before purchase: what do these patents cover in practice, how will they survive challenge, and what enforcement options do they enable? The difference between a patent that looks strong on paper and one that performs in litigation is the difference that matters at the acquisition price.
For Japanese companies with U.S. patent assets considering monetization strategy, and for U.S. and European companies evaluating acquisition of Japanese company patent portfolios, the combination of litigation assessment capability and Japan access — language, relationships, and direct knowledge of how Japanese companies manage IP — is directly relevant to the transaction.
Trade Secrets
Misappropriation · Employment and non-compete disputes · Former joint venture partners
Trade secret litigation arises in three recurring contexts in the YMF Law practice: disputes involving departing employees who take proprietary information to a competitor; disputes with former joint venture or licensing partners who continue to use protected technology after the relationship ends; and technology transfer disputes, particularly between U.S. and Japanese companies, where the boundary between licensed use and misappropriation is contested.
Trade secret cases turn on evidentiary reconstruction — establishing what information existed, when it was taken, and how it was used. That analytical discipline is closely related to the investigative work York began as a federal prosecutor, and it carries directly into civil trade secret practice. The combination of document investigation, witness examination, and expert management that defines effective trade secret litigation is the same combination that defines the patent litigation practice.
For Japanese companies involved in U.S. trade secret disputes — whether as plaintiff or defendant — the Japan dimension is often outcome-determinative. Critical witnesses are Japanese. Key documents are in Japanese. The joint venture or licensing agreement that defines the scope of permitted use was negotiated and understood in Japanese. YMF Law handles that dimension of the case without a translation layer.
Jurisdictions & Technology Scope
U.S. federal courts · ITC · Technology sectors
U.S. FEDERAL COURTS & ITC
U.S. Supreme Court · U.S. Court of Appeals for the Federal Circuit · U.S. Court of Appeals for the Fourth Circuit · District of Columbia · Eastern District of Virginia · District of Delaware · District of New Jersey · Middle District of Pennsylvania · Northern District of Illinois · Western District of North Carolina · Middle District of North Carolina · Eastern District of Pennsylvania · District of Arizona · District of Nevada · District of Utah · District of Idaho · District of Oregon · Northern District of California · Southern District of California · Central District of California · U.S. International Trade Commission
TECHNOLOGY SECTORS
Pharmaceuticals · Biologics · Biotechnology · Medical devices · Semiconductors · Automotive technology · Consumer electronics · Fiber optics · Software and systems · Communications · Digital image processing · Liquid crystal displays · Microprocessor instruction sets · Vehicle crash sensor systems · Iris scanning and identification · Long-haul fiber optic routing · Steel manufacturing · Commercial jet engine design · Genetically modified crops · 2D Barcode Symbology Scanning