Motion For Summary Judgement of Invalidity Denied in Praluent® Litigation


On January 18, 2019, in Amgen v. Sanofi, the ongoing litigation concerning Sanofi and Regeneron’s Praluent® (alirocumab) product, Judge Andrews of the District of Delaware denied Sanofi’s motion for summary judgment that the asserted genus claims directed to monoclonal antibodies that inhibit PCSK9 (such as Amgen’s Repatha® and Sanofi/Regeneron’s Praluent® products) are invalid for lack of written description and enablement.

As we previously reported, in January 2017, the District of Delaware entered a permanent injunction prohibiting the sale of Praluent® after the defendants stipulated to infringement of the asserted claims of the patents and a jury found the claims to be valid.  In October 2017, a Federal Circuit panel reversed and remanded, deciding that it was improper to apply the “newly characterized antigen” test for compliance with § 112 and that post-priority-date evidence can be used to show lack of written description.  The Federal Circuit later denied Amgen’s petition for rehearing en banc, and on January 7, 2019 the Supreme Court denied Amgen’s petition for a writ of certiorari.

The case is now back in the District of Delaware on remand.  On January 18, Judge Andrews denied Sanofi’s motion for summary judgment of lack of written description and enablement, and denied Amgen’s motion for summary judgment of estoppel.

With respect to written description, Judge Andrews held that summary judgment must be denied because there are genuine disputes of material facts regarding both the “common structural features” test and the “representative species” test.  Regarding both tests for written description, Judge Andrews held that disputes between the parties’ experts about the interpretation and significance of the patents’ disclosures constitute genuine disputes of material fact.

With respect to enablement, Judge Andrews found that although the parties “do not dispute that repetition is required to make antibodies within the claimed genus,” there was a genuine dispute of material fact because the “parties’ experts dispute the predictability of this repetition and the amount of time required to make antibodies within the genus from the specification’s disclosures.”

Finally, Judge Andrews denied Amgen’s motion for summary judgment that Sanofi was estopped from making various written description and enablement arguments based on arguments Sanofi made in PTO filings related to unrelated patents.  Judge Andrews found that although some of the arguments Sanofi made in different fora seemed conceptually inconsistent, “the purported inconsistent representations were made in the context of unrelated patent filings with material differences” from the patents at issue in this case, so “even if the representations may be facially inconsistent at first glance,” Amgen had not demonstrated that Sanofi’s “previous representations are so ‘irreconcilably inconsistent’ as to warrant application of judicial estoppel.”

Judge Andrews also granted Sanofi’s motion for judgment on the pleadings of no willful infringement.  Judge Andrews reasoned that Amgen had waived willful infringement by failing to appeal the court’s original judgment of no willfulness as a matter of law.

The case is scheduled for a 3-day jury trial beginning February 19, 2019 on the issues of written description and enablement.

DISCLAIMER: Because of the generality of this update, the information provided herein may not be applicable in all situations and should not be acted upon without specific legal advice based on particular situations.

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