In a recent district court decision, Judge Stark (D. Del.) further clarified the scope of the rights derived from a Patent Term Extension (PTE) during the extension period.
On January 7, 2020, Judge Stark granted a Rule 12(c) motion for judgment on the pleadings in Biogen Int’l GmbH v. Banner Life Sciences, dismissing Biogen’s complaint. Banner sought Food and Drug Administration approval to market “MMF,” the parent drug or “active moiety” of Biogen’s “DMF” prodrug. In response, Biogen asserted a patent claiming a method of treating multiple sclerosis (“MS”) by administering “MMF” (found in Banner’s product), “DMF” (found in Biogen’s product), or a combination of the two. Thus, Biogen’s approved product contained DMF and it had a patent claiming the use of both DMF and the “active moiety” MMF.
In dismissing Biogen’s complaint, the Court concluded that the rights derived from Biogen’s PTE are limited to the approved uses of the approved product. The Court concluded that because Biogen’s approved product contained the prodrug DMF—not Banner’s MMF—its “enforceable, extendable patent rights extend only to DMF.”
The Relevant Products and Patent Claims
Biogen markets Tecfidera, which contains the prodrug DMF for the treatment of MS. Banner sought approval for Bafiertam, which contains MMF, the parent drug or “active moiety” of DMF, for the treatment of MS.
Biogen applied for and obtained a PTE. Claim 1 claims a method of treating MS by administering DMF, MMF, or a combination thereof. Claim 5 claims a method of treating MS by administering MMF.
The Arguments and the Court’s Decision
Banner concedes that its proposed product—containing MMF for the treatment of MS—infringes at least claims 1 and 5 before their natural expiry. However, Banner argued that Biogen’s patent was “only extended, and can only be enforced, with respect to a DMF-containing product.” Because Banner’s proposed product contains MMF, not DMF, it argued that it was entitled to judgment on the pleadings.
The Court agreed. In an apparent case of first impression, the Court analyzed the statutory framework and relevant (at times seemingly contradictory) case law to conclude that Biogen’s PTE rights were limited to use of the DMF-containing products for which Biogen received FDA approval. Importantly, the Federal Circuit had previously limited the scope of the rights derived from a PTE for a patent claiming a product—as opposed to a method here—to the product on which the extension was based. The court found that the same logic should apply to extended method of treatment patents.
The Court then had to consider —“what is the FDA-approved product in this case?” Was it, as argued by Banner, the prodrug DMF (the “active ingredient”) or did it include also, as argued by Biogen, MMF (the “active moiety”)?
In analyzing this further issue, the Court attempted to reconcile two apparently contradictory cases, Glaxo v. Quigg and Pfizer v. Dr. Reddy’s, before concluding that Biogen’s PTE extended only the use of DMF, the “active ingredient” in Biogen’s product. In Glaxo, the Federal Circuit concluded that the term “active ingredient” refers to the “molecule in the drug product . . . not the active moiety.” (emphasis in original). In Pfizer, the Federal Circuit concluded that the term “active ingredient” for “the purposes of PTE was . . . the active moiety.” In reconciling those cases, the Court relied on a subsequent Federal Circuit case, PhotoCure v. Kappos, which held that there was no conflict between those cases because the issue in Pfizer was limited to the question of whether a PTE could be avoided merely by changing the salt of the “active moiety.” A salt change was not at issue in this case.
Accordingly, the Court concluded, based on PhotoCure, that Glaxo controlled and that “Biogen’s enforceable, extended patents rights extend only to DMF,” and did not reach MMF.
This case serves as another example of the developing (and often narrow) interpretation of the statute’s PTE provisions and highlights the need for patent practitioners to contemplate possible narrow interpretations in advising their clients regarding loss of exclusivity on their products. Biogen has filed a notice of appeal.
 Biogen Int’l GmbH v. Banner Life Sciences LLC, C.A. No. 18-2054-LPS (D. Del. Jan. 7, 2020)
 Merck & Co. v. Kessler, 80 F.3d 1543, 1547 (Fed. Cir. 1996).
 Glaxo Operations UK Ltd. V. Quigg, 894 F.2d 392 (Fed. Cir. 1990).
 Pfizer v. Dr. Reddy’s Labs., 359 F.3d 1361 (Fed, Cir. 2004).
 PhotoCure ASA v. Kappos, 603 F.3d 1372 (Fed. Cir. 2010).