Hatch-Waxman and Biosimilar Litigation

Common situations.

• A brand company receives notice that a generic maker has challenged its Orange Book patents.
• A generic maker wants to launch for an unpatented use while a method-of-use patent is still in force.
• A biosimilar applicant decides whether to share its application with the brand.

Small-molecule drugs: the Hatch-Waxman framework.

1. Orange Book listing. A brand lists patents that claim its drug or an approved method of using it. A patent must claim at least the active ingredient to be listed; patents claiming only a device component, such as an inhaler, must be removed (Teva Branded Pharm. Prods. R&D, Inc. v. Amneal Pharms. of N.Y., LLC, No. 2024-1936 (Fed. Cir. Dec. 20, 2024)).
2. The generic application. A generic applicant (ANDA) must certify for each listed patent. A Paragraph IV certification states that the patent is invalid or will not be infringed (21 U.S.C. § 355(j)(2)(A)(vii)(IV)). Alternatively, for a method-of-use patent, the applicant may carve the patented use out of its label with a "section viii" statement (§ 355(j)(2)(A)(viii)).
3. Notice. A Paragraph IV applicant must notify the brand and patent owner, explaining the factual and legal basis for its position (§ 355(j)(2)(B)).
4. Suit and the 30-month stay. Filing the application is an act of infringement (35 U.S.C. § 271(e)(2)). If the brand sues within 45 days after receiving notice, FDA approval is generally stayed for 30 months, unless the court rules sooner (21 U.S.C. § 355(j)(5)(B)(iii)).
5. Exclusivity for the first challenger. The first applicant to file a Paragraph IV certification may receive 180 days of generic marketing exclusivity (§ 355(j)(5)(B)(iv)), subject to forfeiture rules.
6. Trial and remedies. Because no product has been sold, cases are typically tried to the judge. If the patent is valid and infringed, the court orders that FDA approval not take effect before the patent expires (35 U.S.C. § 271(e)(4)).

The same structure applies, with variations, to applications under section 505(b)(2) for modified versions of approved drugs (§ 355(b)(2)).

Skinny labels after Hikma v. Amarin.

A generic maker that carves a patented use out of its label can still be sued for inducing doctors to prescribe for that use. In Hikma Pharmaceuticals USA Inc. v. Amarin Pharma, Inc., No. 24-889 (U.S. June 4, 2026), a unanimous Court held that the complaint did not plausibly allege inducement. Omissions, label content required by law, and ordinary industry practice, such as calling the product a generic of the brand, do not show the active, culpable encouragement that § 271(b) requires. A brand may still sue by alleging clear, affirmative steps designed to promote the patented use. See Types of Patent Infringement.

Correcting the Orange Book.

A generic defendant may counterclaim for an order requiring the brand to correct or delete patent information in the Orange Book (§ 355(j)(5)(C)(ii)(I)), including an overbroad description of a patented use (Caraco Pharm. Labs., Ltd. v. Novo Nordisk A/S, 566 U.S. 399 (2012)). The Federal Trade Commission has also challenged listings it considers improper.

Biologics and biosimilars.

The Biologics Price Competition and Innovation Act sets a different path for biosimilars:

• Exclusivity. FDA may not approve a biosimilar until 12 years after the reference product was first licensed, and may not accept an application until 4 years after (42 U.S.C. § 262(k)(7)).
• The "patent dance." The statute provides for an optional exchange: the applicant shares its application and manufacturing information, and the parties exchange patent lists and contentions, which shape the first wave of litigation (§ 262(l)).
• Notice of commercial marketing. The applicant must give at least 180 days' notice before first commercial marketing, which may be given before FDA approval (§ 262(l)(8)(A); Sandoz Inc. v. Amgen Inc., 582 U.S. 1 (2017)). Federal law does not provide an injunction to compel an applicant to take part in the patent dance (Sandoz).
• Infringement. Submitting a biosimilar application is an act of infringement for patents identified in the exchange (35 U.S.C. § 271(e)(2)(C)). There is no automatic 30-month stay.

Venue and Texas.

Venue in generic drug cases lies only where the defendant resides or where acts related to submitting the application occurred (Valeant Pharms. N. Am. LLC v. Mylan Pharms. Inc., 978 F.3d 1374 (Fed. Cir. 2020)). As a result, most Hatch-Waxman cases are filed in the District of Delaware and the District of New Jersey, and relatively few are filed in Texas. A Texas court is a proper venue only when a generic defendant resides in the district or carried out acts related to its application there.

Settlements.

Payments from a brand to a generic challenger to delay entry can violate the antitrust laws (FTC v. Actavis, Inc., 570 U.S. 136 (2013)), and certain brand-generic and biosimilar settlements must be filed with the FTC and the Department of Justice. See Settlement and Licensing.

Sources.

• 21 U.S.C. §§ 355(b)(2), 355(j).
• 35 U.S.C. §§ 271(e)(1), (e)(2), (e)(4).
• 42 U.S.C. § 262(k), (l).
• Hikma Pharms. USA Inc. v. Amarin Pharma, Inc., No. 24-889 (U.S. June 4, 2026).
• Teva Branded Pharm. Prods. R&D, Inc. v. Amneal Pharms. of N.Y., LLC, No. 2024-1936 (Fed. Cir. Dec. 20, 2024).
• Caraco Pharm. Labs., Ltd. v. Novo Nordisk A/S, 566 U.S. 399 (2012).
• Sandoz Inc. v. Amgen Inc., 582 U.S. 1 (2017).
• Valeant Pharms. N. Am. LLC v. Mylan Pharms. Inc., 978 F.3d 1374 (Fed. Cir. 2020).
• FTC v. Actavis, Inc., 570 U.S. 136 (2013).

This guide is general information, not legal advice. Law checked through October 20, 2026. See the Disclaimer.