Recent Decisions and FTC Challenges Dictate Caution When Listing Patents in the Orange Book

In October 2023, Teva Pharmaceuticals filed a patent infringement lawsuit against Amneal Pharmaceuticals alleging that their generic version of Teva’s ProAir® HFA inhaler infringed upon the asserted claims of U.S. Patent Nos. 8,132,712, 9,463,289, 9,808,587, 10,561,808, and 11,395,889.¹ The lawsuit automatically triggered a 30-month stay under the Hatch-Waxman Act, potentially preventing Food and Drug Administration (FDA) approval of Amneal’s generic inhaler until February 2026.

The Hatch-Waxman Act allows generic drug manufacturers to challenge branded drug patents through the filing of a Paragraph IV certification and notifying the patent holder. If the branded company files a lawsuit against the generic within 45 days, the FDA is required to delay approval of the generic drug for up to 30 months while the litigation proceeds. It is important to note that this stay applies only to patents listed in the Orange Book — an issue central to the Teva v. Amneal dispute.

Following Teva’s lawsuit, Amneal filed counterclaims, including alleged antitrust violations, seeking to delist Teva’s inhaler patents from the Orange Book.² Teva countered and argued that the patents were properly listed and that any antitrust allegations should be dismissed.²

The Federal Trade Commission (FTC) submitted an amicus brief advocating for the removal of Teva’s inhaler patents from the Orange Book, asserting that improper listings wrongly delay approval of competing generic products.³ The FTC had earlier issued warning letters to 10 brand pharmaceutical companies that challenged over 100 patents, contending that the patents were improperly listed in the Orange Book.⁴ The FTC emphasized that only patents claiming the active ingredient of a drug (or its method of treatment) should be listed, while patents related to drug-device combinations should not.

In June 2024, Judge Stanley Chesler of the U.S. District Court for the District of New Jersey ruled on both Teva’s motion to dismiss and Amneal’s cross-motion for judgement on the pleadings. He first examined the “Listing Statute” that governs which patents must be listed in the FDA’s Orange Book for a New Drug Application (NDA) holder (21 U.S. Code § 355(b)(1)(A)(viii)).¹ To be listable, patents must claim either: (1) the drug itself (either the active ingredient or the formulation of the drug), or (2) a method of using the drug. As per the Listing Statute, Judge Chesler ruled that Teva’s patents for its ProAir® HFA did not meet the statutory requirements. Specifically, the listed patents covered the inhaler device itself, not the active ingredient (albuterol sulfate) or its formulation. As a result, he concluded that these patents should not have been listed in the Orange Book because they do not meet the statutory criteria. Thus, Judge Chesler denied Teva’s motion to dismiss and granted Amneal’s motion for judgement, and ordered Teva to delist the challenged patents from the Orange Book. Teva appealed this decision, and at Teva’s request for a stay pending appeal, Judge Chesler granted a 30-day stay of his ruling in order to give the Court of Appeals for the Federal Circuit time to consider Teva’s request for a stay of the delisting order.²

In December 2024, the Federal Circuit affirmed the District Court’s decision and rejected Teva’s argument that its listing of the inhaler patents in the Orange Book was proper. Teva had argued that the inhaler patents, which cover components like a dose counter and canister, should be listed because they related to the ProAir® HFA inhaler.² However, the Federal Circuit ruled that the Listing Statute requires a patent to both claim the drug (specifically its active ingredient) and cover the NDA product itself. However, Teva’s patents did not claim the active ingredient, only the component of the inhaler. The court also rejected Teva’s argument that any component of a drug-delivery device qualifies as a “drug” under the Food, Drug, and Cosmetic Act, emphasizing that the statute distinguishes between drugs and devices.² Finally, the court declined to remand the case for claim construction, as even under Teva’s proposed interpretation the patents did not claim the active ingredient and were therefore not listable in the Orange Book.

On January 22, 2025, the Federal Circuit stayed the delisting order in response to Teva’s request for an en banc rehearing. This halts the removal of Teva’s patents from the Orange Book until the court decides whether to grant Teva’s request for a full-court rehearing.^5,6 AstraZeneca and Sanofi-Aventis filed amicus briefs backing Teva’s request, arguing that the decision could negatively impact both brand companies and the generic industry by disrupting the established process for resolving patent disputes.⁷

This decision highlights the importance of accurate Orange Book listings because the FTC takes a strict, active approach to ensure compliance with antitrust concerns. In its policy statement, the FTC has indicated that improper Orange Book listings could be considered anti-competitive behavior and potentially violate Section 5 of the Federal Trade Commission Act.⁸ As such, pharmaceutical companies should exercise caution and carefully evaluate Orange Book patent listings to avoid legal and regulatory issues.