Line design
Halaven® (eribulin mesylate)
GENERICally Speaking

Case Name: Eisai R&D Mgmt. Co., Ltd. v. Dr Reddy’s Labs., Inc., No. 22-CV-5950, 2023 WL 7331272 (D.N.J. Nov. 7, 2023) (Chesler, J.)

Drug Product and Patent(s)-in-Suit: Halaven® (eribulin mesylate); U.S. Patents Nos. 6,214,865 (“the ’865 patent”) and RE46,965 (“the ’965 patent”)

Nature of the Case and Issue(s) Presented: DRL’s ANDA contained two different certifications: a paragraph III certification to the 865 patent and a paragraph IV certification to the 965 patent. After offering DRL a covenant not to sue on the 965 patent, Eisai moved to dismiss all claims and counterclaims on the basis that the court lacked subject-matter jurisdiction. The court granted Eisai’s motion.

Why Eisai Prevailed: After DRL filed its ANDA, Eisai filed a complaint asserting infringement of the 965 patent. Shortly after, Eisai delivered DRL a covenant not to sue on the 965 patent. DRL’s opposition brief explained that Eisai tendered a limited and conditional covenant not to sue. Prior to oral argument, Eisai issued a revised covenant not to sue that contained no defects. The court acknowledged that Eisai had a “formidable burden” to demonstrate that it could not reasonably be expected to resume its enforcement efforts, but that the revised covenant extinguished an actual or real controversy between the parties as to Eisai’s claims against DRL.

The court next turned to Eisai’s motion to dismiss DRL’s counterclaims, explaining that there “is no bright-line rule for determining whether an action satisfies the case or controversy requirement.” DRL argued that a case and controversy existed because it is blocked from receiving final approval given the first ANDA applicant may have 180-day market exclusivity. More particularly, DRL argued that the first ANDA applicant may forfeit its 180-day market exclusivity if another ANDA applicant, such as DRL, secures a final court decision in its favor on the 965 patent. In response, Eisai argued that DRL’s allegation that the first-filer “may” have market exclusivity and that a judgment in favor of DRL “may” trigger such exclusivity was too speculative for subject-matter jurisdiction. The court found that the record supported an inference that the first filer had forfeited its 180 days of exclusivity because it failed to obtain approval within 30 months. For this reason, the court granted Eisai’s motion to dismiss DRL’s counterclaims.

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