Filgrastim, pegfilgrastim biosimilar litigation updates

Below is a rundown of some recent developments in BPCIA litigations concerning biosimilars of Neupogen® (filgrastim) and/or Neulasta® (pegfilgrastim).

Amgen v. Adello (filgrastim)

As we previously reported, in March, Amgen filed a complaint for patent infringement against Adello Biologics based on its filing of an aBLA for a filgrastim biosimilar.  On May 17, Adello answered the complaint, asserting defenses and counterclaims that the 17 patents-in-suit are invalid and not infringed.

Amgen v. Coherus (pegfilgrastim)

Also on May 17, Amgen appealed to the Federal Circuit from the district court’s final judgment of non-infringement of Amgen’s protein purification process patent, U.S. Patent No. 8,273,707, in favor of Coherus. The Federal Circuit has docketed the appeal as Case No. 18-1993.  Amgen’s opening brief is due on July 20.

Amgen v. Mylan (pegfilgrastim)

Earlier this month, the parties completed briefing regarding Mylan’s motion for judgment on the pleadings regarding Amgen’s assertion of U.S. Patent No. 8,273,707 in view of the decision in the related Coherus case regarding this patent.  In its opposition, Amgen argues that Mylan’s motion is premature and that judgment on the pleadings is inappropriate because (a) Amgen’s complaint and detailed statement regarding infringement that it provided to Mylan during the patent dance pursuant to subsection (l)(3)(C) state more than a plausible claim for relief, (b) Mylan’s process satisfies all the claim limitations, literally or under the doctrine of equivalents, (c) Amgen’s infringement claims are not precluded by prosecution history estoppel, and (d) the Coherus decision is inapplicable to this case.  In reply, Mylan argues, among other things, that Amgen’s equivalence and literal infringement positions are foreclosed based on Amgen’s disclaimer of patent scope during patent prosecution.

Amgen v. Sandoz (filgrastim and pegfilgrastim)

Last month, Amgen filed its opening appeal brief with the Federal Circuit in its appeal from the district court’s grant of Sandoz’s motion for summary judgment of non-infringement.  In its brief, Amgen argues that the district court made several errors in construing the claims of Amgen’s asserted protein purification patent (U.S. Patent No. 8,940,878) and method of treatment patent (U.S. Patent No.6,162,427), which led incorrectly to final judgments of non-infringement for each of those patents.  Amgen summarizes the issues on appeal as follows:

  1. Whether the district court erred as a matter of law in construing the “washing” and “eluting” elements of claim 7 of U.S. Patent No. 8,940,878 where:
    1. the district court originally interpreted “eluting the protein from the separation matrix” to occur after “washing the separation matrix” and required “washing” and “eluting” to be accomplished by applying “a solution”;
    2. but on summary judgment, the district court imposed additional limitations that washing and eluting must be accomplished by applying different solutions that are temporally and compositionally distinct.
  2. Whether the district court erred as a matter of law in granting summary judgment of non-infringement of claim 7 of the ’878 Patent with respect to Sandoz’s current process for manufacturing its biosimilar products where Amgen presented evidence that Sandoz’s process meets the claim limitations.
  3. Whether the district court erred as a matter of law in granting summary judgment of non-infringement of claim 7 of the ’878 Patent and denying Amgen’s motion for additional discovery pursuant to Rule 56(d) with respect to Sandoz’s modified process for manufacturing its biosimilar products (which were still under development and had not yet been submitted to FDA), where Sandoz did not provide complete information about the process, denying Amgen discovery on the very way Sandoz will make its biosimilar products going forward.
  4. Whether the district court erred in construing “chemotherapeutic agent” as used in claim 1 of U.S. Patent No. 6,162,427 to be for treatment of disease rather than working in combination with G-CSF to enhance stem cell mobilization.


Sandoz’s responsive appeal brief is due June 22, in light of the Federal Circuit’s grant last week of an extension, over Amgen’s objection. Amgen had argued that Sandoz’s requested extension was unreasonable and prejudicial to Amgen because, among other things, “this appeal involves Sandoz’s attempt to obtain FDA approval for a [pegfilgrastim] biosimilar product that is not on the market; the timely resolution of this appeal is meaningful because it impacts Amgen’s ability to obtain relief as to its patent infringement claims before any FDA approval.”

Stay tuned to Big Molecule Watch for further developments in these and other BPCIA litigations.