Why is Amgen doubling-down on its psoriasis patents in the Enbrel® patent case against Sandoz?

Zachary Silbersher

The much-anticipated trial in the biosimilar litigation over Enbrel® has been pushed from April, to June and now to September.  Although Amgen ($AMGN) has asserted five patents against Sandoz’s ($NVS) proposed biosimilar, Erelzi®, the focus of the case has been on the two Roche patents directed to the entanercept protein itself.  And yet, a skirmish has erupted related to one of the three other patents, which collectively cover indications for using entanercept to treat psoriasis indications.

Sandoz initially sought approval of its Erelzi® biosimilar for several indications, including psoriasis indications.  Likewise, Amgen sued Sandoz for infringement of three patents that purport to cover those psoriasis indications.  In September 2017, Amgen moved for summary judgment that one of the psoriasis patents (the ‘631 patent) was infringed. 

The psoriasis patents, however, were presumably not as material to the litigation.  They will expire shortly in 2019, and even so, Sandoz could theoretically carve out psoriasis indications for its biosimilar to avoid infringement.  Indeed, that is what Sandoz has done.  It filed a request with FDA to remove psoriatic arthritis and plaque psoriasis indications from its label for Erelzi®.  That request was granted, and the amended label, according to Sandoz, no longer contains indications for psoriatic arthritis or plaque psoriasis.  In light of the amended label dropping the psoriasis indications, Sandoz has argued that Amgen’s summary judgment motion is moot.  Amgen has disagreed, and persisted in keeping the motion alive. 

Under the biosimilar statute, as well as the Hatch-Waxman statute for small-molecule generics, it is technically considered an act of infringement to file an BLA or ANDA with the FDA.  The whole point of these statutes is to accelerate resolution of claims of patent infringement that will inevitably accompany the launch of a generic or biosimilar drug.  Thus, rather than waiting for the launch, the statutes permit commencing suit long before the launch.  Yet, under the Patent Statute, you cannot technically sue someone for patent infringement until that person actually infringes the patent—i.e., by making, selling or offering to sell an allegedly infringing product.  The biosimilar statute creates a runaround that problem.  It provides that just by filing an BLA, that grants the innovator drug company standing to sue for infringement immediately. 

Accordingly, Amgen argues that regardless of whether Sandoz has amended its label, its earlier act of filing a BLA to market an entanercept biosimilar for psoriasis remains an act of infringement.  And Amgen demands summary judgment on that.  Amgen argues Sandoz will nevertheless induce infringement.  “Inducement” is a theory of indirect infringement.  Direct infringement of patent occurs when you sell a product that infringes the patent, whereas indirect infringement occurs when you encourage or induce someone else to infringe the patent. 

Here, Amgen argues that, even if the label has been changed, and even if the amended label will not prospectively infringe the patent directly, Sandoz has already repeatedly told the public that its entanercept biosimilar will be effective in treating psoriasis.  That includes the EGALITY study, which studied treatment of Sandoz’s biosimilar for patients with psoriasis.  Those public statements cannot be clawed back, and thus, in theory, could potentially subject Sandoz to liability for indirectly inducing doctors to prescribe its biosimilar for off-label psoriasis indications.

But, ultimately, why does it matter?  Even Amgen admits that its summary judgment motion itself is not about inducement, even though Amgen preserves the right to argue inducement at trial.  (See 16-cv-1118) (D.N.J.) (Dkt. 446).  So, if Amgen is not arguing inducement in its summary judgment motion, and if Sandoz has really changed the label, then why does Amgen insist on gaining summary judgment of the ‘691 patent based only upon Sandoz’s technical act of filing its original BLA with a label that has now been admittedly amended? 

There are obviously certain technical reasons for doubling down on a seemingly moot motion, to the extent it shores up future arguments.  Yet, in one of the briefs, Sandoz argues there Amgen is masking the “true purpose” of its motion, and the Court should not be complicit in facilitating Amgen’s “scheme.”  (See 16-cv-1118) (D.N.J.) (Dkt. 448-1 at 2).  What is that scheme?  Sandoz refers to another brief filed by Amgen, where Amgen purportedly describes the scheme.  (See 16-cv-1118) (D.N.J.) (Dkt. 312 at 8).  Yet, the relevant portions of that brief—much like so much on the docket of this case—is redacted and not publicly-available.  Amgen appears to be arguing that, despite the amendment to the label, the originally filed BLA and other acts by Sandoz will rebound and have effects that will harm Amgen.  And it needs a judgment that the original label infringed the psoriasis patents in order to claim relief for those “effects.” 

It is not clear why so much of this case is filed under seal and redacted.  Given the importance of this case to Amgen, investors should demand more transparency into exactly what Amgen is arguing, or at the very least, explanations why this transparency is not possible.