The battle over the proper forum for patent infringement litigation regarding Dupixent® (Dupilumab) appears to have been resolved.  Last week, on May 1, 2017, Sanofi, Genzyme, and Regeneron voluntarily dismissed their Declaratory Judgment Complaint in the District of Massachusetts (Civ. No. 17-cv-10465).  The dismissal, however, does not resolve the underlying patent infringement dispute, which is still the subject of a separate pending litigation in the Central District of California (Civ. No.  17-cv-01623).  Nor does the dismissal resolve the substantive dispute over patent validity, which is the subject of an IPR petition pending at the PTAB (IPR2017-01129).

The dispute began on March 20, 2017, when Sanofi-Aventis U.S. LLC, Genzyme Corporation, and Regeneron Pharmaceuticals, Inc. filed a Complaint against Amgen, Inc. and Immunex Corp. in the United States District Court for the District of Massachusetts seeking a declaratory judgment that their Dupixent® (dupilumab) does not infringe U.S. Patent No. 8,679,487 (“the ’487 patent”) as we reported in this post.  Just a few days later, Sanofi, Genzyme, and Regeneron file a petition for inter partes review of the ’487 patent, as discussed here.  At that time, Dupixent® had not yet been approved, but Regeneron and Sanofi announced that the FDA had granted final approval to the product on March 28, 2017.

The following week, on April 5, 2017, Immunex filed  a separate Complaint in the United States District Court for the Central District of California alleging infringement of the ’487 patent.  Then, on April 11, 2017, Immunex filed a motion to dismiss the Massachusetts case or to transfer the case to California, setting up a battle over the litigation forum, as we reported in this post.   Meanwhile, in the California case, on April 19, 2017, the parties filed a joint stipulation extending Sanofi, Genzyme, and Regeneron’s time to file an Answer from May 5, 2017 to May 26, 2017.

Rather than file an opposition to the motion to dismiss, Sanofi, Genzyme, and Regeneron filed an Amended Complaint in the Massachusetts case on April 24, 2017.  The Amended Complaint set forth additional facts in support of personal and subject matter jurisdiction in the Massachusetts Court.  The following day, on April 25, 2017, Judge Gorton entered an Order in the Massachusetts case denying Immunex’s motion to dismiss or transfer as moot (in view of the Amended Complaint).  A discussion of the Plaintiffs’ reasons for dismissing the suit after having defeated the initial motion to dismiss or transfer would be speculation.

The time for Sanofi, Genzyme, and Regeneron to Answer or otherwise respond to the Complaint in the California district court litigation is still a few weeks away, and a scheduling order has not yet been entered.  However, given that there is only one patent at issue in the litigation, and that same patent is the subject of a petition for IPR, it is possible that the district court litigation will be stayed if the IPR proceeding is instituted.  Immunex’s preliminary response in the IPR petition is currently due no later than July 6, 2017, and the PTAB should issue a decision on institution three months later, in early October of this year.  Stay tuned for future developments.