Antitrust Law Daily Wrap Up, ANTITRUST NEWS—4th Cir.: FTC: Amgen’s Enbrel patent-application deal is subject to antitrust scrutiny, (Aug 18, 2026)

By Martin A. Steinberg, J.D.

Agency says acquisitions of pending patent applications can violate the Sherman Act and are not shielded by Noerr-Pennington merely because the patents are later prosecuted and enforced.

The FTC, appearing as amicus curiae in support of neither party, urged the Fourth Circuit to reject Amgen Inc.’s bid to categorically shield its acquisition of exclusive rights to pending patent applications from antitrust scrutiny, arguing that such acquisitions can constitute exclusionary conduct under Section 2 of the Sherman Act and are not immunized by the Noerr-Pennington doctrine merely because the applications were later prosecuted before the U.S. Patent and Trademark Office and the resulting patents enforced in court. The FTC maintained that Amgen’s 2004 acquisition of exclusive rights to Roche patent applications related to Enbrel allegedly helped extend Amgen’s monopoly by years and that the underlying commercial transaction must be analyzed separately from later protected petitioning activity. Separately, in one of two other recently filed amicus briefs, the American Antitrust Institute likewise supported affirmance, emphasizing that CareFirst need only plausibly plead causation and antitrust injury at the motion-to-dismiss stage and that implied antitrust immunities should be narrowly construed. In another brief, the Open Markets Institute similarly argued that mergers and acquisitions, including acquisitions of pending patent applications, can constitute unlawful monopolization when used to acquire or maintain monopoly power (CareFirst of Maryland, Inc. v. Amgen Inc., No. 26-1473 (4th Cir. Aug. 14, 2026)).

Background. The dispute concerns Amgen’s patent rights covering Enbrel, a biologic drug used to treat inflammatory diseases such as rheumatoid arthritis. Immunex Corporation obtained a series of patents covering Enbrel’s active ingredient and launched the drug in the United States in 1998. Roche, however, had earlier filed patent applications describing etanercept, Enbrel’s active ingredient, giving Roche priority rights to the technology used in the drug. Immunex therefore obtained a nonexclusive license to Roche’s relevant patent rights. At the same time, Roche retained the ability to either commercialize a competing product itself or license the technology to another potential competitor.

After Enbrel became commercially successful, Amgen acquired Immunex and took over marketing the drug. With Immunex’s principal Enbrel patents scheduled to expire in 2012, Amgen restructured the Roche licensing arrangement in 2004. Under the new agreement, Amgen obtained exclusive rights to the etanercept patent family, including control over prosecution of two pending Roche patent applications and the right to enforce resulting patents against companies seeking to market etanercept biosimilars. The FTC notes that the transaction underwent Hart-Scott-Rodino review and received early termination of the waiting period, but stresses that such termination was not a determination that the transaction was lawful and did not preclude later antitrust scrutiny.

The two pending Roche applications subsequently became central to Amgen’s continued exclusivity. The USPTO issued patents from them in 2011 and 2012, extending patent protection relating to Enbrel through 2029. Amgen then relied on those patents to obtain permanent injunctions against biosimilar competitors Sandoz and Bioepis, with the injunctions lasting until the patents expire in April 2029, 17 years after Amgen’s earlier Enbrel patents expired in 2012.

CareFirst of Maryland, Inc. thereafter filed a putative class action complaint alleging that Amgen’s acquisition of the Roche patent applications constituted exclusionary conduct that unlawfully maintained its Enbrel monopoly in violation of Section 2 of the Sherman Act. Amgen moved to dismiss, arguing that acquiring pending patent applications cannot constitute anticompetitive conduct as a matter of law and that Noerr-Pennington protected the transaction because Amgen later prosecuted the applications and enforced the resulting patents in court. The district court rejected both arguments, holding that the subsequent petitioning activity could be protected while the underlying acquisition remained potentially actionable, and certified those questions for interlocutory appeal.

Acquisitions of patent applications not immune. The FTC argues that Amgen cannot categorically shield acquisitions of pending patent applications from Section 2 scrutiny. Acquiring patent rights can constitute exclusionary conduct when it increases or prolongs monopoly power, and the agency contends that the same principle applies to pending applications. Supreme Court precedent has treated acquisitions of patents and patent applications as potentially anticompetitive, and distinguishing the two would create an arbitrary rule under which a monopolist could avoid liability by acquiring a rival’s application immediately before patent issuance.

Pending applications can pose competitive concerns. Although a patent application is less certain than an issued patent, the FTC argues that it can provide strategic advantages that are themselves competitively significant. Control over prosecution permits the applicant to amend or add claims as competitors and technologies develop. An acquired application also carries its original priority date, which can shield later claims from intervening prior art. It may support continuation applications, allowing the company to pursue new claims over time. Because the ultimate scope of those claims remains uncertain, pending applications can also deter competitors from investing, developing products, or entering the market.

The FTC says Amgen’s acquisition of exclusive rights to the Roche applications illustrates those concerns. Amgen already held a nonexclusive license to market Enbrel, but in 2004 obtained exclusive control over two Roche patent applications. It subsequently altered the claims, and the resulting patents ultimately extended Enbrel-related exclusivity through 2029.

The agency rejects Amgen’s argument that applications are too speculative to have exclusionary significance. Issued patents are also probabilistic because their validity and infringement remain subject to challenge, and antitrust law routinely addresses conduct involving uncertain future competitive effects. The FTC also notes that it considers pending applications in merger review and consent orders because they can affect future competition. It characterizes an application not as a mere request for rights, but as an inchoate property right in a continuum that can mature into an issued patent.

Antitrust scrutiny would not stifle innovation. The FTC also disputes Amgen’s contention that recognizing potential liability would discourage innovation. Most intellectual-property licenses, particularly nonexclusive arrangements, are procompetitive and unlikely to raise concerns. The narrower problem arises when a dominant firm obtains exclusive rights from an actual or potential competitor in a transaction that may suppress competition.

According to the FTC, licensing an invention to a noncompetitor to facilitate commercialization differs fundamentally from a monopolist’s acquisition of substitute technology that could otherwise support competing entry. The agency argues that antitrust scrutiny of the latter category protects, rather than undermines, innovation by preventing dominant firms from extending monopoly positions through exclusive acquisitions instead of competing on the merits.

Not protected under Noerr-Pennington. The FTC argues that Noerr-Pennington protects Amgen’s later petitioning activity, prosecuting the patent applications before the USPTO and enforcing the resulting patents in court, but does not immunize the earlier commercial transaction through which Amgen acquired exclusive rights to Roche’s applications. The doctrine protects efforts to influence government action, not otherwise anticompetitive private conduct merely because petitioning later occurs.

The acquisition and later petitioning are distinct. The FTC relies on decisions holding that protected litigation does not retroactively immunize earlier anticompetitive conduct. The Second Circuit held in PrimeTime 24 Joint Venture v. National Broadcasting Co., 219 F.3d 92 (2d Cir. 2000), that copyright holders could not shield an allegedly anticompetitive licensing agreement simply because they later pursued infringement litigation. Likewise, Amphastar Pharmaceuticals, Inc. v. Momenta Pharmaceuticals, Inc., 850 F.3d 52, 57 (1st Cir. 2017), held that a later patent suit did not immunize earlier conduct alleged to violate the Sherman Act. The FTC contends that the same principle applies here: even if Amgen’s patent prosecution and infringement suits were protected petitioning, the alleged Section 2 violation was the acquisition itself.

According to the FTC, Amgen’s contrary rule would create sweeping practical problems. Any anticompetitive agreement could potentially gain immunity if followed by some form of government petitioning. A patent acquisition could become protected once the purchaser sued for infringement, while the identical acquisition would remain actionable if rivals simply stayed out of the market. The agency argues that antitrust liability should not turn on whether protected petitioning happens later.

Antitrust violation and antitrust injury are separate issues. The FTC also argues that Amgen improperly conflates the existence of an antitrust violation with whether CareFirst suffered antitrust injury. Whether conduct violates the antitrust laws is analytically distinct from whether a private plaintiff can show injury caused by that violation. Thus, even if CareFirst ultimately cannot prove compensable injury, that would not mean Noerr-Pennington immunizes Amgen’s underlying acquisition. The FTC expressly takes no position on whether CareFirst can satisfy the requirements for private antitrust injury.

The acquisition was not merely “incidental” to petitioning. The FTC further rejects Amgen’s argument that acquiring the applications was protected because it was “incidental” to later USPTO petitioning. Courts have extended Noerr-Pennington beyond direct petitioning only to closely related conduct lacking independent commercial significance, such as settlement offers, threats of litigation, or litigation funding.

Amgen’s transaction, by contrast, was a standalone commercial acquisition with independent economic value. The acquired applications could be sold, licensed, or used strategically regardless of whether Amgen ever prosecuted them further. In the FTC’s view, the petitioning was therefore subordinate to the acquisition, not the other way around.

The agency warns that Amgen’s approach would extend Noerr-Pennington well beyond patent law. If accepted, acquisitions of assets undergoing FDA approval or other regulatory review could likewise be characterized as “incidental” to later petitioning. The FTC concludes that the doctrine should remain limited to protecting actual petitioning and closely related conduct, while leaving independent commercial transactions subject to ordinary antitrust scrutiny.

American Antitrust Institute amicus brief. In its amicus curiae brief supporting CareFirst and affirmance, the American Antitrust Institute focused on pleading standards, causation, and the narrow scope of implied antitrust immunity. AAI argued that CareFirst need only plausibly allege that Amgen’s exclusive licensing agreement with Roche materially contributed to higher prices and need not disprove, at the motion-to-dismiss stage, Amgen’s competing theory that subsequent patent-enforcement injunctions caused the injury. It further contended that Noerr-Pennington should not be extended to immunize the underlying commercial acquisition of Roche’s patent rights merely because Amgen later petitioned the USPTO and courts. In AAI’s view, patent law and antitrust law are complementary systems, and exempting acquisitions of pending patent applications from antitrust review could allow monopolists to extend market power without corresponding innovation benefits.

Open Markets Institute amicus brief. In its amicus curiae brief supporting CareFirst, the Open Markets Institute likewise urged affirmance, emphasizing that Section 2 of the Sherman Act broadly reaches acquisitions used to obtain or maintain monopoly power, including acquisitions of patents and pending patent applications. Open Markets argued that pending applications have real competitive and exclusionary value because they can deter entry, be licensed, and later mature into enforceable patents. It characterized Amgen’s acquisition of Roche’s pending Enbrel-related applications as a potentially exclusionary asset acquisition that allegedly enabled Amgen to block biosimilar competition and extend its monopoly. The brief therefore urged the court to reject any categorical rule insulating pending patent acquisitions from Section 2 scrutiny.

The Case is No. 26-1473.

Attorneys: Hannah W. Brennan (Hagens, Berman, Sobol, Shapiro, LLP) for CareFirst of Maryland, Inc. Elaine Janet Goldenberg (Munger, Tolles & Olson LLP) for Amgen Inc.

Companies: CareFirst of Maryland, Inc.; Amgen Inc.

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