Kinevac® (sincalide)
Case Name: Bracco Diagnostics Inc. v. Maia Pharms., Inc., No. 2020-1387, 2020 WL 7393233 (Fed. Cir. Dec. 17, 2020) (Circuit Judges Lourie, Clevenger, and Chen presiding; Opinion by Lourie, J.) (Appeal from D. N.J., Sheridan, J.)
Drug Product and Patent(s)-in-Suit: Kinevac® (sincalide); U.S. Patent No. 6,803,046 (“the ’046 patent”)
Nature of the Case and Issue(s) Presented: Bracco sued Maia, alleging infringement of the ’046 patent, which covered Bracco’s drug sincalide, sold under the trade name Kinevac. Sincalide was a synthetic peptide hormone, typically administered to stimulate gallbladder contraction, stimulate pancreatic secretion, and accelerate the transit of a barium meal through the small bowel. Claim 1 of the ’046 patent recited, in relevant part, a formulation comprising “a surfactant/solubilizer … and, a buffer.” Maia’s accused product contained amino acid excipients, which Bracco contended satisfied the “surfactant/solubilizer” and “buffer” limitations of the asserted claims. Of note, several dependent claims of the ’046 patent contained Markush groups, which further stated that surfactants/solubilizers or buffers could be selected from a list of excipients that included amino acids. The district court construed the terms to include the amino acid excipients found in Maia’s sincalide product, and listed compounds from the Markush groups, in its definition. Given the district court’s constructions, the parties stipulated to infringement of certain claims and the district court entered judgment accordingly. Maia appealed to the Federal Circuit to vacate the district court’s claim constructions, adopt its proposed constructions, and to remand to the case for further proceedings. The Federal Circuit Court affirmed the district court’s judgment.
Why Plaintiff Prevailed: The Federal Circuit began by noting that for the purposes of claim construction, the Markush groups were “closed because use of transitional phrase ‘consisting of’ to set off a patent claim element indicates that the claim ‘excludes any elements, steps, or ingredients not specified in the claim.” As such, due to the Markush groups, the dependent claims needed no formal construction because the possible components were named and the scope of the dependent claims was definite and clear.
As to the “buffer” claim limitation, Maia argued that the district court’s construction of the term was contrary to its plain and ordinary meaning because per the ’046 patent, buffering agents are employed to stabilize the pH of sincalide formulations, and the district court eliminated this functional aspect by construing it to include amino acids that do not necessarily have buffering effects. Maia made similar arguments as to the “surfactant/solubilizer” claim limitations. Maia also argued that the district court improperly included the list of compounds from the Markush groups in its definition of the claim limitations.
While the Federal Circuit agreed with Maia that the district court erred in importing a list of compounds from the Markush groups into its definition of the claim limitations, this was a harmless error that did not frustrate the task of claim construction, which is “to provide definitional meaning to claim language.” The Federal Circuit held that the district court correctly defined the claim terms for the purposes of the invention. Further, the Federal Circuit held that the parties’ stipulation should be given effect as an admission of infringement based on the clear language of the stipulation. While Maia argued that it had no choice but to stipulate to infringement based on the district court’s construction, the Court rejected this argument as Maia had asked the Court to “effectively reinterpret the court’s construction” and Maia had stipulated to infringement based on that construction.
