At the end of last month, Judge Connolly denied defendants Hospira and Pfizer’s motion to dismiss following a telephone conference with the parties. We previously reported back in February 2020 that Amgen sued Pfizer and its affiliate Hospira for patent infringement of U.S. Patent No. 8,273,707 (“’707 patent”) based on their proposed biosimilar of NEULASTA (pegfilgrastim). The ’707 patent claims processes for purifying proteins that require, among other limitations, using two specified salts “wherein the concentration of each of the first salt and the second salt in the mixture is between about 0.1 M and about 1.0 [M].”
On March 4, 2020, defendants filed a motion to dismiss for failure to state a claim, asserting that Pfizer’s process does not meet the concentration limitation as a matter of law, and further arguing that this was the “second time Amgen has sued a biosimilar manufacturer in this Court alleging infringement of [U.S. Patent No. 8,273,707].” They asserted that “[t]he first lawsuit, against Coherus, ended with a dismissal under Rule 12(b)(6) [for failure to state a claim], affirmed by the Federal Circuit, based on Amgen’s concessions made during patent prosecution.” Defendants argued that the present case should be dismissed for similar reasons. Plaintiffs responded in their Answering Brief that Amgen “did not distinguish its invention from the prior art based on a particular concentration of salt, but rather on which and how many salts were employed and Amgen’s statements in the prosecution of the parent are not a disclaimer as to the salt concentrations claimed in the patent.” Defendants responded in their reply briefing that their motion to dismiss turned on a single legal issue, namely “whether Amgen clearly and unmistakably surrendered salt concentrations below 0.040 M during prosecution.”
We will continue to monitor developments in this case.