Recently, the Federal Circuit Court of Appeals dismissed Pfizer Inc.’s (“Pfizer”) appeal for lack of Article III standing. Pfizer had filed an inter partes review (“IPR”) against Chugai Pharmaceutical Co. (“Chugai”) arguing that U.S. Patent Nos. 7,332,289 and 7,927,815 (“the patents-at-issue”) were unpatentable. The patents at issue are directed towards methods of manufacturing rituximab. Specifically, the patents at issue recite purifying proteins by “removing contaminant DNA from a sample containing a physiologically active protein.” The PTAB held that the claims were not invalid and Pfizer appealed.

To establish standing, an appellant must show that it suffered an injury in fact that is traceable to the appellee’s conduct and that is likely to be redressed by a judicial decision in the appellant’s favor.[1] The Federal Circuit explained that when an appellant is not engaging in infringing conduct, in order to demonstrate an actual injury-in-fact in an IPR appeal, the appellant must show that “it has concrete plans for future activity that creates a substantial risk of future infringement or would likely cause the patentee to assert a claim of infringement.”[2]

In support of its argument for standing, Pfizer relied on the FDA’s approval of its product Ruxience® in July 2019, and an announcement in Oct. 2019 that Pfizer would begin selling its product in Jan. 2020.  Ruxience® is a biosimilar to Genentech, Inc.’s rituximab product. Pfizer argued that when it launched its biosimilar product in Jan. 2020, Chugai was likely to file an infringement lawsuit for the patents-at-issue because Pfizer’s Ruxience® concerns purifying the protein using Protein A chromatography.

Pfizer further argued that it had standing because it was “self-evident” that a product existed at the time it filed its appeal. Pfizer relied on the fact that its service email address for the IPR proceedings was Pfizer also relied on the fact that Chugai listed Genentech, Inc., as a potential real party in interest in the IPR proceedings because Genentech sells a rituximab product and is a subsidiary of F. Hoffmann-La Roche AG, which is an owner of Chugai.

However, the Federal Circuit rejected these arguments and held that Pfizer failed to establish a concrete injury as of the filing of its appeal in Jan. 2019. The Federal Circuit held that any evidence that Pfizer submitted regarding its activities or plans for its biosimilar product occurred after the date of the appeal. The Federal Circuit further held that Pfizer failed to provide sufficient evidence demonstrating its intent to practice the patented methods when manufacturing Ruxience®. As such, because Pfizer failed to establish standing, the Federal Circuit dismissed the appeal.

The Federal Circuit also rejected Pfizer’s argument that the statutory estoppel effect of 35 U.S.C. § 315(e) increases Pfizer’s interest in the outcome of the case. The Federal Circuit held that the statutory estoppel effect does not establish an injury-in-fact when there is no evidence that the appellant engaged in any activity that would lead to an infringement lawsuit.


The Federal Circuit’s dismissal demonstrates the importance of the timing of filing an IPR petition. Any challenger can have standing to file an IPR petition. But in order to appeal an unfavorable decision, the challenger must also have Article III standing, which recent Federal Circuit decisions illustrate may be easier said than done. While the standing requirements are more relaxed when a party is challenging an agency action, the bar remains high.  Generally, parties succeed at establishing an injury in fact when there is a real threat of an infringement suit. The mere fear of future litigation occurring at an undetermined time or the existence of a competitive relationship are not enough. The Federal Circuit has found standing to be satisfied if a party can demonstrate that it intends to engage in infringing activity, it has the capability to do so, and that its product may be infringing.[3] Thus, when a party is not currently faced with litigation, it must collect strong evidence to show it suffered a concrete injury.

However, as this current decision shows, a challenger must not only demonstrate a concrete injury-in-fact, but the injury must have occurred prior to the filing of a notice of appeal. Thus, potential petitioners should carefully consider the opportune time to file the petition and be sure that it aligns with their own activities and product development.

[1] See Op. at 3.

[2] See Op. at 4.

[3] Altaire Pharm., Inc. v. Paragon Bioteck, Inc., 889 F.3d 1274, 1282–83 (Fed. Cir. 2018).