IP Law Daily, PATENT—3d Cir.: Celltrion must await final ruling before challenging Amgen’s foreign tribunal discovery request, (Jun 6, 2025)

By Saurabh Kashyap, B.A., M.A., LL.B., LL.M.

The appeal was deemed premature as the discovery order lacked finality under 28 U.S.C. § 1291.

The U.S. Court of Appeals for the Third Circuit dismissed an appeal by Celltrion USA, Inc. challenging a district court order that granted Amgen Inc.’s application for discovery under 28 U.S.C. § 1782. The court ruled that because the order left the scope of discovery undefined, it was not a final decision under 28 U.S.C. § 1291 and thus not subject to immediate appeal. Further, the appellate court held that appellate review must await the district court’s conclusive determination of discovery obligations, aligning with decisions from the Fifth and Ninth Circuits (In re Application of Amgen Inc., No. 25-1407 (3d Cir. June 5, 2025)).

Background. The appellee, Amgen Inc., is a U.S.-based biotechnology company that develops therapeutic biologics, including denosumab, a monoclonal antibody used to treat bone cancer and skeletal-related conditions. Amgen holds patents covering the composition and manufacturing processes of denosumab in both the United States and South Korea. The appellant, Celltrion Inc., developed a biosimilar version of denosumab and announced its intent to launch in the U.S. in October 2024. In response, Amgen and its affiliate initiated patent infringement suits in both countries against Celltrion Inc., alleging unauthorized use of its patented technology.

On April 5, 2024, Amgen filed a § 1782 application in the District of New Jersey seeking to compel Celltrion to produce 82 categories of documents and deposition testimony for use in the South Korean litigation. Amgen argued that Celltrion had relevant information on development, regulatory submissions, and product strategy pertaining to the denosumab biosimilar, even if the documents originated from its South Korean parent.

Celltrion opposed the application, contending that § 1782 cannot be used to compel a U.S. subsidiary to produce materials belonging to a foreign parent company and further asserted that the request was unduly burdensome under the standard articulated in Intel Corp. v. Advanced Micro Devices, Inc., 542 U.S. 241 (2004). Nevertheless, a U.S. Magistrate Judge granted Amgen's application, holding that Celltrion resided in the district and rejecting its threshold argument regarding extraterritoriality. The judge found that overbreadth alone was not grounds for denying a § 1782 application and deferred the determination of specific objections until a later stage. The parties were instructed to meet and confer on confidentiality terms and the scope of discovery. Celltrion appealed to the district court, which affirmed the magistrate judge’s order. It then filed the instant appeal to the Third Circuit.

Finality under § 1291. The appellate court concluded that the district court’s order granting Amgen’s § 1782 application, without resolving the exact scope of permissible discovery, was not a “final decision” appealable under 28 U.S.C. § 1291. Citing Weber v. McGrogan, 939 F.3d 232, 236 (3d Cir. 2019), the court reiterated that a decision is final only when it “ends the litigation on the merits and leaves nothing for the court to do but execute the judgment.”

The court emphasized that the district court’s order explicitly required the parties to confer on discovery issues and stated that compliance would be subject to further objections. This open-ended language indicated that substantial judicial work remained before Celltrion’s obligations could be clearly determined. As such, the order was interlocutory and not ripe for appellate review.

Intel framework requires discovery scope. The court also addressed the practical difficulties of evaluating § 1782 orders without a defined scope of discovery. Under the four-factor test set out in Intel Corp., appellate courts review a district court's discretion in granting discovery. However, the Third Circuit observed that such a review "cannot occur in a vacuum" and depends on the nature and extent of the discovery ordered. Without knowing what specific documents or categories were compelled, the court found it impossible to determine whether the lower court had abused its discretion under the Intel framework.

Alignment with other circuits. The Third Circuit aligned its reasoning with that of the Fifth and Ninth Circuits. In CPC Patent Technologies Pty Ltd. v. Apple, Inc., 119 F.4th 1126, 1133 (9th Cir. 2024), the Ninth Circuit dismissed an appeal from a § 1782 order that left discovery obligations undefined, noting that the lack of clarity precluded finality. Similarly, in Banca Pueyo SA v. Lone Star Fund IX (U.S.), L.P., 978 F.3d 968, 974 (5th Cir. 2020), the Fifth Circuit dismissed an appeal of a § 1782 order where a motion to quash was pending, and the discovery scope had not been fixed. The Third Circuit expressly adopted these decisions, holding that “a conclusive determination as to the scope of [a party’s] discovery obligations” is essential for finality under § 1291.

Distinguishing Heraeus. The appellate court rejected Celltrion’s reliance on Heraeus Kulzer, GmbH v. Biomet, Inc., 881 F.3d 550 (7th Cir. 2018). In Heraeus, the Seventh Circuit found appellate jurisdiction where a motion to modify a protective order was conclusively denied years after the initial § 1782 discovery grant. The Third Circuit noted that Heraeus involved a fully resolved post-judgment issue, unlike the pending case, where the parties remain in the early stages of defining discovery terms. Thus, Heraeus supported, rather than undermined, the principle that only conclusive rulings are final under § 1291.

Conclusion. Because the order granting discovery under § 1782 left the scope of discovery undefined and required further action by the district court, the Third Circuit concluded it lacked jurisdiction under 28 U.S.C. § 1291. The court dismissed the appeal without prejudice, leaving Celltrion free to seek appellate review after a final discovery determination was issued.

The Case is No. 25-1407.

Judge: Per Curiam.

Attorneys: Joshua J. Fougere (Sidley Austin LLP for Amgen Inc. Jonathan Y. Ellis (McGuireWoods LLP) for Celltrion USA Inc.

Companies: Amgen Inc.; Celltrion USA Inc.

Cases: Patent OhioNews NewJerseyNews PennsylvaniaNews