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April 10, 2025
In a formulation claim, if elements are listed separately, does this necessarily entail that those elements are “separate and distinct components”? This was the question before the district court in Regeneron Pharmaceuticals, Inc. v. Mylan Pharmaceuticals Inc. et al. and up for appeal at the Federal Circuit. The district court denied Regeneron’s motion for a preliminary injunction against Defendant Amgen because the claim elements at issue were “separate and distinct components” and therefore, Regeneron “failed to establish a likelihood of success” in showing that Amgen infringed its patent, U.S. Patent No. 11,084,865 (“the ’865 patent”). Specifically, Regeneron challenged the district court’s claim construction opinion, and application of Becton, Dickinson & Co. v. Tyco Healthcare Grp., LP, 616 F.3d 1249 (Fed. Cir. 2010) (“Becton”).
Regeneron’s ’865 patent is directed to formulations of fusion protein, aflibercept, which Regeneron markets as EYLEA®. Regeneron Pharm., Inc. v. Mylan Pharm. Inc., C.A. No. 24-2351, at 3 (Fed. Cir. Mar. 14, 2025). Defendant Amgen filed an abbreviated Biologics License Application to market ABP 938 (now known as Pavblu), a biosimilar of EYLEA®. Id. at 3. Unlike EYLEA®, Amgen’s formulation contains “a version of the fusion protein aflibercept,” but it does not contain a separate buffer component. Id. at 4. An excerpt of representative claim 1 of the ’865 patent requires a formulation that comprises:
a vascular endothelial growth factor (VEGF) antagonist
an organic co-solvent,
a buffer,
and a stabilizing agent. . . .
Id. at 4. The question at issue concerned whether the claims required the VEGF antagonist and buffer to be “separate and distinct components of the claimed formulation.” Id. at 5. If yes, then Amgen does not necessarily infringe the ’865 patent because Amgen’s product does not contain a separate buffer component.
The Federal Circuit affirmed the district court’s application of Becton. The Federal Circuit reviewed the district court’s claim construction opinion based on intrinsic evidence de novo and any findings of fact regarding extrinsic evidence for clear error. Id. at 8. The district court applied Becton, which established a presumption that “where a claim lists elements separately, the clear implication of the claim language is that those elements are distinct components of the patented invention.” Id. at 6. The district court then decided “whether the evidence overcame ‘the clear implication’ of separateness under Becton.” Id. at 6. Applying Becton, the district court found that the presumption of separateness applied. The VEGF antagonist and buffer were separate components and neither intrinsic nor extrinsic evidence overcame this clear implication of separateness. Therefore, the district court denied Regeneron’s motion for a preliminary injunction because Amgen had raised a substantial question of noninfringement. Id. at 6, 8.
First, the Federal Circuit determined that Becton applied because “the plain language of the claim recites a formulation comprising four separately listed components.” Id. at 8. As claim one identified four separately listed components, “the plain language of the claim therefore establishes a ‘clear implication’ that the VEGF antagonist and buffer components are distinct components of the claimed formulation.” Id. at 9-10. The Federal Circuit found that “the district court did properly engage with the claims, consistent with [Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005)] and established claim construction principles.” Id. at 10. The Federal Circuit determined that the district court correctly applied Becton.
Second, the Federal Circuit found that evidence did not overcome the implication of separateness under Becton. “[T]o overcome Becton, there must be evidence that shows that the impliedly distinct components, instead can be satisfied by a single component.” Id. at 12. Looking at the intrinsic evidence, the district court found that “all of the claims of the ’865 patent treat the ‘VEGF antagonist’ as separate from the ‘buffer,’” the claims list the components with “different concentrations and different units of measurement,” and the specification describes “a formulation containing a VEGF antagonist plus a distinct buffer component.”1 Id. at 13, 14. Next, the Federal Circuit found that the district court did not need to consider the “extrinsic evidence for claim construction where, as here, the intrinsic evidence is clear and unambiguous.” Id. at 17. Upon review, the district court found that “none of the extrinsic evidence discloses that aflibercept can function as a buffer in a pharmaceutical formulation.” Id. at 17. Regeneron pointed to International Patent Application Publication WO 2006/138181 as identifying that “‘biopharmaceutical proteins’ could ‘be formulated in self-buffering components.’” Id. at 18. Though, the Federal Circuit found that this extrinsic evidence supports the VEGF antagonist and buffer as separate components because self-buffering proteins were not well known. Id. at 18-19.
Therefore, the Federal Circuit affirmed the district court’s denial of Regeneron’s preliminary injunction because the VEGF antagonist and buffer claim limitations were “separate and distinct components,” there was a substantial question of noninfringement, and Regeneron had not established a likelihood of success on the merits of its infringement allegation.