Pharmaceutical patent disputes run on a statutory clock of Paragraph IV certifications and the 30-month stay, in a branded-versus-generic contest that decides when a product can reach the market. We litigate the patents with the regulatory framework in view.
A Paragraph IV notice letter gives the brand 45 days to sue. If it does, FDA approval of the generic is stayed for 30 months counted from the day the notice was received, not from the day the complaint was filed, and the stay is available only for patents listed in the Orange Book before the ANDA was submitted. Those two details shape the case more than any claim construction.
The statute, the Drug Price Competition and Patent Term Restoration Act of 1984, makes the generic's filing itself an act of infringement so the patents can be tried before a single tablet is sold. With nothing sold there are no damages to win; the remedy is an order resetting the generic's approval date to the patent's expiry, and the whole case is tried to the bench. The first generic to certify earns 180 days of market exclusivity.
We act for innovators enforcing Orange Book patents and for generic and life-sciences applicants challenging them, subject to conflicts, and we bring in registered patent counsel and FDA regulatory counsel where the prosecution history or the application itself is in issue.
Advising on the Paragraph IV certification that starts an ANDA dispute, covering its drafting, its notice requirements, and the litigation it can trigger, so the filing and the case strategy are planned together rather than in sequence.
Managing the 45-day window to sue and the resulting 30-month stay of FDA approval. We calculate the timeline, preserve or contest the stay, and align the litigation schedule with the regulatory clock that governs launch.
Representing innovator manufacturers enforcing Orange Book-listed patents against generic applicants. We build the infringement case, defend validity, and protect the exclusivity on which a flagship product depends.
Representing generic applicants and life-sciences ventures challenging listed patents, with invalidity and non-infringement positions, design-around analysis, and a path to the launch the branded patents would otherwise block.
Working the patent dispute alongside the FDA framework of Orange Book listings, ANDA filings, and exclusivity questions, and coordinating with FDA-focused counsel where the application itself is in issue as well as the patents.
Carrying the matter through claim construction, expert discovery, and trial in federal court, with settlement and licensing options weighed throughout and appellate strategy coordinated with registered patent counsel where required.
The stay does not stay the litigation, and a court may shorten or lengthen it when a party fails to cooperate in expediting the case. The FDA can grant tentative approval meanwhile, so the generic ships when it lifts. A schedule that misses that date decides the case by default.
Only patents claiming the drug substance, the drug product or an approved method of use are listable; process patents are not. The FDA does not check, so listing is the brand's call, and a generic defendant can counterclaim to delist. The FTC has disputed more than 400 listings since 2023.
Section 271(e)(1) lets a generic make and test the drug to prepare its application without infringing. Section 271(e)(2) then makes a Paragraph IV filing an artificial act of infringement, so the case is tried before launch. Until a commercial launch there are no damages; the remedy is the approval date.
A generic can sidestep a method-of-use patent by carving the patented indication out of its label under section viii rather than certifying against it. The carve-out holds only if what remains does not still encourage the patented use; the Federal Circuit has found inducement where it did.
Trial counsel litigate the patents in federal court, while prosecution before the USPTO requires registered patent counsel. Where a matter needs that input, it is coordinated rather than improvised.
A generic may launch at risk once the stay expires, even mid-appeal; if it later loses, damages are the brand's lost profits. A payment for delay is judged under the rule of reason, and every brand-generic settlement is filed with the FTC and Justice Department within ten business days.
The Paragraph IV notice letter arrives with its detailed statement of invalidity and non-infringement, and the branded side has 45 days to sue or forfeit the stay. We read the Orange Book listing, the certification, and the patent estate together, because the decision to file is made against a clock that has already started.
Filing within the window triggers the 30-month stay of FDA approval, and the case is planned around that runway: consolidated multi-defendant dockets, protective orders over the ANDA itself, and a schedule negotiated with the stay's expiration date as the fixed point every deadline works back from.
Discovery runs through the ANDA specification, batch records, and formulation science, and claim construction and expert reports frame obviousness, enablement, and infringement of the proposed generic. The record is prepared for a bench trial, since Hatch-Waxman cases are tried to the court rather than to a jury.
The endgame is a date on the market calendar. It arrives as a judgment under 35 U.S.C. § 271(e)(4) resetting approval, a settlement with acceptable-launch terms cleared for FTC/DOJ filing, or an at-risk launch decision weighed against treble-scale exposure. Either way, what the client takes away is the calendar.
In Hatch-Waxman, the remedy is a date, and every motion is really an argument about the calendar.
Hatch-Waxman litigation is the patent dispute framework created by the Drug Price Competition and Patent Term Restoration Act of 1984, which governs how generic drug makers seek FDA approval through an Abbreviated New Drug Application (ANDA) while branded manufacturers enforce the patents listed in the Orange Book. When a generic applicant files a Paragraph IV certification asserting that a listed patent is invalid or not infringed, the resulting case follows a distinct statutory timeline that sets it apart from ordinary patent litigation.
A Paragraph IV certification is the statement a generic applicant files in its ANDA asserting that an Orange Book-listed patent is invalid, unenforceable, or will not be infringed by the proposed generic product. Filing it is treated as an act of infringement that can trigger litigation, and serving the required notice starts the clock on the branded manufacturer's window to sue and on the potential 30-month stay of FDA approval.
A statutory bar on final FDA approval of the generic that applies when the brand sues within 45 days of receiving the Paragraph IV notice. It runs 30 months from the date the notice was received, not from the filing of the suit, so a brand that waits until day 44 has spent six weeks of its own runway. The stay is available only for patents listed in the Orange Book before the ANDA was submitted, and only once per application; a patent listed later earns no new stay. A court may shorten or lengthen it where a party has failed to reasonably cooperate in expediting the case. The FDA may grant tentative approval while it runs, and the stay ends early if the generic wins in the district court.
Hart David Carson LLP advises clients on both sides of the branded-versus-generic divide, subject to conflict clearance: branded manufacturers enforcing Orange Book patents, and life-sciences ventures and generic applicants challenging them. The posture changes the strategy, but the statutory architecture is the same, and we shape the case to fit the client's position within it.
Patent litigation can be conducted by trial counsel admitted to the relevant federal court, while patent prosecution before the USPTO requires registration with the Patent Office. Where a matter calls for registered patent agents or prosecution counsel, or for FDA regulatory input on the underlying application, we coordinate with registered counsel and FDA-focused advisers so the litigation strategy and the technical record stay aligned.
The patent case and the approval process run on the same calendar. The ANDA is a regulatory filing, the Orange Book listing is a self-certified FDA record, and the 30-month stay operates on the FDA's approval decision, not the court's schedule. Tentative approval can issue during the stay, so a generic is ready to launch the day it lifts. The first applicant to file a Paragraph IV certification earns 180 days of marketing exclusivity, forfeited by failing to market in time or to obtain tentative approval within 30 months of filing. A section viii carve-out avoids a method-of-use patent by removing the indication from the label, and FDA's acceptance of the carve-out is a regulatory question that lands in the middle of the infringement case. We bring in FDA regulatory counsel where the application itself is in issue.
Trial advocacy in patent infringement and validity disputes across technologies, from claim construction and expert discovery through trial in federal court.
Explore →Exclusion-order and unfair-import investigations before the International Trade Commission, the fast-moving forum that runs parallel to district-court patent disputes.
Explore →Inter partes review and other proceedings before the Patent Trial and Appeal Board, the administrative challenge to patent validity that often shadows a litigation.
Explore →Enforcement and defense of trademark and copyright rights, covering infringement, dilution, and the protection of brand and creative assets.
Explore →Reviewed by Jonathan D. Herpy, Sr., Senior Partner · Last updated October 2026 · Educational overview · Not legal advice
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